chore: rename workflow to main

for consistency with other repos

.github/workflows/main.yml

@@ -0,0 +1,44 @@
+name: main
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn
+
+      - name: Get changed files
+        id: changed-files
+        uses: tj-actions/changed-files@v44
+        with:
+          files: |
+            packages/**/*.{nr,toml}
+
+      - if: steps.changed-files.outputs.any_changed == 'true'
+        name: Install Nargo
+        uses: noir-lang/[email protected]
+        with:
+          toolchain: 0.26.0
+
+      - if: steps.changed-files.outputs.any_changed == 'true'
+        name: Test circuits
+        run: yarn test