fix(action): update cache paths in setup-build-environment and build workflows for consistency

Co-authored-by: Copilot <copilot@github.com>

.github/actions/setup-build-environment/action.yml

@@ -10,13 +10,13 @@ runs:
 
         # Setup ccache for both build.sh and Bazel
         sudo apt-get update && sudo apt-get install -y ccache
-        export CCACHE_DIR="$GITHUB_WORKSPACE/kernel/.ccache"
+        export CCACHE_DIR="$GITHUB_WORKSPACE/kernel/common/.ccache"
         export CC="ccache gcc"
         export CXX="ccache g++"
-        echo "CCACHE_DIR=$GITHUB_WORKSPACE/kernel/.ccache" >> "$GITHUB_ENV"
+        echo "CCACHE_DIR=$GITHUB_WORKSPACE/kernel/common/.ccache" >> "$GITHUB_ENV"
         echo "CC='ccache gcc'" >> "$GITHUB_ENV"
         echo "CXX='ccache g++'" >> "$GITHUB_ENV"
-        echo "$GITHUB_WORKSPACE/kernel/.ccache" > "$GITHUB_PATH"
+        echo "$GITHUB_WORKSPACE/kernel/common/.ccache" > "$GITHUB_PATH"
 
         # For Bazel (kleaf), set up remote and disk cache if needed
         echo "BAZEL_CACHE_DIR=$GITHUB_WORKSPACE/.cache/bazel" >> "$GITHUB_ENV"

.github/workflows/build.yml

@@ -191,7 +191,7 @@ jobs:
       id: restore-ccache
       uses: ./.github/actions/restore-cache
       with:
-        cache_path: ${{ github.workspace }}/kernel/.ccache
+        cache_path: ${{ github.workspace }}/kernel/common/.ccache
         cache_key: buildcache-${{ inputs.kernel_version }}
         cache_bucket: "ccache-cache"
         compression_level: 9
@@ -210,7 +210,7 @@ jobs:
       id: restore-ldcache
       uses: ./.github/actions/restore-cache
       with:
-        cache_path: ${{ github.workspace }}/kernel/.ld_cache
+        cache_path: ${{ github.workspace }}/kernel/common/.ld_cache
         cache_key: buildcache-${{ inputs.kernel_version }}
         cache_bucket: "lto-cache"
         compression_level: 9
@@ -234,8 +234,8 @@ jobs:
         pre_misses=$(echo "$stats" | awk '/cache miss/ {m+=$NF} END{print (m+0)}')
         echo "pre_hits=$pre_hits" >> $GITHUB_OUTPUT
         echo "pre_misses=$pre_misses" >> $GITHUB_OUTPUT
-        pre_ld_size=$(du -sh "$GITHUB_WORKSPACE/kernel/.ld_cache" 2>/dev/null | awk '{print $1}' || echo "0B")
-        pre_ld_files=$(find "$GITHUB_WORKSPACE/kernel/.ld_cache" -type f 2>/dev/null | wc -l || true)
+        pre_ld_size=$(du -sh "$GITHUB_WORKSPACE/kernel/common/.ld_cache" 2>/dev/null | awk '{print $1}' || echo "0B")
+        pre_ld_files=$(find "$GITHUB_WORKSPACE/kernel/common/.ld_cache" -type f 2>/dev/null | wc -l || true)
         echo "pre_ld_size=$pre_ld_size" >> $GITHUB_OUTPUT
         echo "pre_ld_files=$pre_ld_files" >> $GITHUB_OUTPUT
 
@@ -263,8 +263,8 @@ jobs:
         else
           echo "No compiler activity detected (no ccache accesses)."
         fi
-        post_ld_size=$(du -sh "$GITHUB_WORKSPACE/kernel/.ld_cache" 2>/dev/null | awk '{print $1}' || echo "0B")
-        post_ld_files=$(find "$GITHUB_WORKSPACE/kernel/.ld_cache" -type f 2>/dev/null | wc -l || true)
+        post_ld_size=$(du -sh "$GITHUB_WORKSPACE/kernel/common/.ld_cache" 2>/dev/null | awk '{print $1}' || echo "0B")
+        post_ld_files=$(find "$GITHUB_WORKSPACE/kernel/common/.ld_cache" -type f 2>/dev/null | wc -l || true)
         echo "ld_cache size before: ${{ steps.pre-cache-stats.outputs.pre_ld_size }}, after: $post_ld_size"
         echo "ld_cache files before: ${{ steps.pre-cache-stats.outputs.pre_ld_files }}, after: $post_ld_files"
 
@@ -272,16 +272,16 @@ jobs:
       working-directory: ${{ github.workspace }}
       run: |
         echo "=== .ccache ==="
-        du -sh kernel/.ccache || true
-        ls -l kernel/.ccache || true
+        du -sh kernel/common/.ccache || true
+        ls -l kernel/common/.ccache || true
         echo "=== .cache/bazel ==="
-        du -sh kernel/.cache/bazel || true
-        ls -l kernel/.cache/bazel || true
+        du -sh kernel/common/.cache/bazel || true
+        ls -l kernel/common/.cache/bazel || true
 
     - name: Save ccache cache
       uses: ./.github/actions/save-cache
       with:
-        cache_path: ${{ github.workspace }}/kernel/.ccache
+        cache_path: ${{ github.workspace }}/kernel/common/.ccache
         cache_key: buildcache-${{ inputs.kernel_version }}
         cache_bucket: "ccache-cache"
         compression_level: 9
@@ -290,7 +290,7 @@ jobs:
     - name: Save LTO LD cache
       uses: ./.github/actions/save-cache
       with:
-        cache_path: ${{ github.workspace }}/kernel/.ld_cache
+        cache_path: ${{ github.workspace }}/kernel/common/.ld_cache
         cache_key: buildcache-${{ inputs.kernel_version }}
         cache_bucket: "lto-cache"
         compression_level: 9