Bump actions/upload-artifact from 3 to 4

.github/workflows/manage-prs.yml

@@ -5,7 +5,7 @@
   MAINTAINERS: |
     # GitHub user names to request reviews from in cases where PRs can't be managed automatically.
     - per1234
-  CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT: check-submissions-failed
+  CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PREFIX: check-submissions-failed-
   ERROR_MESSAGE_PREFIX: ":x: **ERROR:** "
 
 on:
@@ -103,7 +103,7 @@
                 --output "${{ steps.configuration.outputs.path }}/{}" \
                 --header "Authorization: token $GITHUB_TOKEN" \
                 --header "Accept: application/vnd.github.v3.{}" \
                 https://api.github.com/repos/${{ github.repository_owner }}/${{ github.event.repository.name }}/pulls/${{ github.event.pull_request.number }}${{ github.event.issue.number }}
             ' \
             ::: \
               ${{ env.DIFF_IDENTIFIER }} \
@@ -114,7 +114,7 @@
         run: echo "::set-output name=head::$(jq -c .head.sha "${{ steps.configuration.outputs.path }}/${{ env.JSON_IDENTIFIER }}")"
 
       - name: Upload diff file to workflow artifact
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           path: ${{ steps.configuration.outputs.path }}/${{ steps.configuration.outputs.filename }}
           name: ${{ steps.configuration.outputs.artifact }}
@@ -144,13 +144,13 @@
           location: ${{ runner.temp }}
 
       - name: Download diff
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           path: ${{ needs.diff.outputs.path }}
           name: ${{ needs.diff.outputs.artifact }}
 
       - name: Remove no longer needed artifact
-        uses: geekyeggo/delete-artifact@v2
+        uses: geekyeggo/delete-artifact@v5
         with:
           name: ${{ needs.diff.outputs.artifact }}
 
@@ -376,16 +376,23 @@
         if: env.PASS == 'false'
         run: touch ${{ env.FAIL_FLAG_PATH }} # Arbitrary file to provide content for the flag artifact
 
+      # Each workflow artifact must have a unique name. The job matrix doesn't provide a guaranteed unique string to use
+      # for a name so it is necessary to generate one.
+      - name: Generate unique artifact suffix
+        if: env.PASS == 'false'
+        run: |
+          echo "CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_SUFFIX=$(cat /proc/sys/kernel/random/uuid)" >> "$GITHUB_ENV"
+
       # The value of a job matrix output is set by whichever job happened to run last, not of use for this application.
       # So it's necessary to use an alternative means of indicating that at least one submission failed the checks.
       - name: Upload failure flag artifact
         if: env.PASS == 'false'
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           if-no-files-found: error
           include-hidden-files: true
           path: ${{ env.FAIL_FLAG_PATH }}
-          name: ${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT }}
+          name: ${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PREFIX }}${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_SUFFIX }}
 
   check-submissions-result:
     needs: check-submissions
@@ -394,13 +401,22 @@
     outputs:
       pass: ${{ steps.failure-flag-exists.outcome == 'failure' }}
 
+    env:
+      CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PATH: ${{ github.workspace }}/artifacts
+
     steps:
+      - name: Download submission check failure flag artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: ${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PATH }}
+          pattern: ${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PREFIX }}*
+
       - name: Check for existence of submission check failure flag artifact
         id: failure-flag-exists
-        uses: actions/download-artifact@v3
         continue-on-error: true
-        with:
-          name: ${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT }}
+        # actions/download-artifact does not create a folder per its `path` input if no artifacts match `pattern`.
+        run: |
+          test -d "${{ env.CHECK_SUBMISSIONS_FAIL_FLAG_ARTIFACT_PATH }}"
 
   check-submissions-fail:
     needs:

.github/workflows/sync-labels.yml

@@ -19,7 +19,7 @@
 
 env:
   CONFIGURATIONS_FOLDER: .github/label-configuration-files
-  CONFIGURATIONS_ARTIFACT: label-configuration-files
+  CONFIGURATIONS_ARTIFACT_PREFIX: label-configuration-file-
 
 jobs:
   check:
@@ -67,16 +67,16 @@
       - name: Download
         uses: carlosperate/download-file-action@v2
         with:
           file-url: https://raw.githubusercontent.com/arduino/tooling-project-assets/main/workflow-templates/assets/sync-labels/${{ matrix.filename }}
 
       - name: Pass configuration files to next job via workflow artifact
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           path: |
             *.yaml
             *.yml
           if-no-files-found: error
-          name: ${{ env.CONFIGURATIONS_ARTIFACT }}
+          name: ${{ env.CONFIGURATIONS_ARTIFACT_PREFIX }}${{ matrix.filename }}
 
   sync:
     needs: download
@@ -85,7 +85,7 @@
     steps:
       - name: Set environment variables
         run: |
           # See: https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-environment-variable
           echo "MERGED_CONFIGURATION_PATH=${{ runner.temp }}/labels.yml" >> "$GITHUB_ENV"
 
       - name: Determine whether to dry run
@@ -107,16 +107,17 @@
       - name: Checkout repository
         uses: actions/checkout@v4
 
-      - name: Download configuration files artifact
-        uses: actions/download-artifact@v3
+      - name: Download configuration file artifacts
+        uses: actions/download-artifact@v4
         with:
-          name: ${{ env.CONFIGURATIONS_ARTIFACT }}
+          merge-multiple: true
+          pattern: ${{ env.CONFIGURATIONS_ARTIFACT_PREFIX }}*
           path: ${{ env.CONFIGURATIONS_FOLDER }}
 
-      - name: Remove unneeded artifact
-        uses: geekyeggo/delete-artifact@v2
+      - name: Remove unneeded artifacts
+        uses: geekyeggo/delete-artifact@v5
         with:
-          name: ${{ env.CONFIGURATIONS_ARTIFACT }}
+          name: ${{ env.CONFIGURATIONS_ARTIFACT_PREFIX }}*
 
       - name: Merge label configuration files
         run: |