Fix ccache handling

Goal: Accumulate ccache for builds on a specific distro and architecture
Problem: Cannot overwrite existing cache. Need to manually delete it beforehand.

.github/workflows/build.yaml

@@ -149,16 +149,15 @@ jobs:
           name: debs
           path: ${{ env.DEBS_PATH }}
 
+      - name: Determine CCACHE_ID
+        id: ccache-id
+        run: echo "CCACHE_ID=ccache-${DEB_DISTRO}-$(dpkg --print-architecture)-${ROS_SOURCES}" | tee -a "$GITHUB_OUTPUT"
       - name: Restore ccache
         id: restore-ccache
         uses: actions/cache/restore@v4
-        env:
-          CCACHE_ID: "ccache-${{ inputs.DEB_DISTRO || vars.DEB_DISTRO }}-${{ inputs.ROS_SOURCES || vars.ROS_SOURCES }}"
         with:
           path: ${{ env.CCACHE_DIR }}
-          key: ${{ env.CCACHE_ID }}-${{ github.run_id }}
-          restore-keys: |
-            ${{ env.CCACHE_ID }}
+          key: ${{ steps.ccache-id.outputs.CCACHE_ID }}
 
       - name: Build .deb packages
         uses: ubi-agni/ros-builder-action@main
@@ -181,6 +180,12 @@ jobs:
         if: always() # always prepare files for upload
         run: find ${{ env.DEBS_PATH }} -name '*[<>:"\\|?*]*' -print -delete
 
+      - name: Delete old ccache
+        if: always() && steps.restore-ccache.outputs.cache-hit
+        continue-on-error: true
+        run: gh cache delete "${{ steps.restore-ccache.outputs.cache-primary-key }}"
+        env:
+          GH_TOKEN: ${{ github.token }}
       - name: Store ccache
         uses: actions/cache/save@v4
         if: always() # save cache on timeout or cancel too