feat(action): add cache directory to Bazel build command and list cache contents for visibility

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

.github/actions/build-kernel/action.yml

@@ -33,5 +33,5 @@ runs:
           SKIP_MRPROPER=1 SKIP_EXT_MODULES=1 SKIP_CP_KERNEL_HDR=1 GKI_DEFCONFIG_FRAGMENT="$GITHUB_WORKSPACE/wild_gki.fragment" BUILD_CONFIG=common/build.config.gki.aarch64 CC="$CC" CXX="$CXX" build/build.sh
         else
           cp "$GITHUB_WORKSPACE/wild_gki.fragment" common/arch/arm64/configs/wild_gki.fragment
-          tools/bazel build --config=release --notrim --defconfig_fragment=//common:arch/arm64/configs/wild_gki.fragment //common:kernel_aarch64
+          tools/bazel build --config=release --notrim --defconfig_fragment=//common:arch/arm64/configs/wild_gki.fragment --cache_dir=$GITHUB_WORKSPACE/kernel/.cache/bazel //common:kernel_aarch64
         fi

.github/workflows/build.yml

@@ -217,6 +217,7 @@ jobs:
       uses: ./.github/actions/build-kernel
 
     - name: List cache contents
+      working-directory: ${{ github.workspace }}/kernel
       run: |
         echo "=== .ccache ==="
         du -sh .ccache || true