save metrics for faster testing -- REVERT before merge

.github/workflows/build-metrics.yml

@@ -59,7 +59,14 @@ jobs:
         # it doesn't work
         run: git config --global --add safe.directory /__w/velox/velox
 
+      - uses: assignUser/stash/restore@v1
+        id: get-bm
+        with:
+          path: '/tmp/metrics'
+          key: build-metrics-${{ matrix.type }}
+
       - name: Make ${{ matrix.type }} Build
+        if: ${{ steps.get-bm.outputs.stash-hit != 'true' }}
         env:
           MAKEFLAGS: 'NUM_THREADS=4 MAX_HIGH_MEM_JOBS=2 MAX_LINK_JOBS=2'
         run: |
@@ -77,6 +84,7 @@ jobs:
           make '${{ matrix.type }}'
 
       - name: Log binary sizes
+        if: ${{ steps.get-bm.outputs.stash-hit != 'true' }}
         run: |
           mkdir -p /tmp/metrics
           sizes_file=/tmp/metrics/object_sizes
@@ -92,8 +100,15 @@ jobs:
             awk '{print $5, $9; total += $5} END {print total," total_exec_size"}' >> $sizes_file
 
       - name: Copy ninja_log
+        if: ${{ steps.get-bm.outputs.stash-hit != 'true' }}
         run: cp _build/release/.ninja_log /tmp/metrics/.ninja_log
 
+      - uses: assignUser/stash/save@v1
+        if: ${{ steps.get-bm.outputs.stash-hit != 'true' }}
+        with:
+          path: '/tmp/metrics'
+          key: build-metrics-${{ matrix.type }}
+
       - name: "Install dependencies"
         run: |
           python3 -m pip install setuptools