message: Use ccache instead of bazel cache.
  The bazel cache action is deprecated, and also does not
  work correctly: it seems to restore an older version, while
  the ccache rule attempts to version it to get a recent one.
diff: @@ -98,13 +98,6 @@ jobs:
  # Download complete repository + tags
  fetch-depth: 0
  - - name: Mount bazel cache
  - uses: actions/cache@v1
  - if: matrix.mode != 'clean' && matrix.mode != 'coverage'
  - with:
  - path: "/home/runner/.cache/bazel"
  - key: bazel-${{ matrix.mode }}
  -
  - name: Install Dependencies
  run: |
  set -x
  @@ -114,6 +107,17 @@ jobs:
  ./.github/bin/install-bazel.sh
  ./.github/bin/install-python.sh
  + - name: Use ccache
  + if: matrix.mode != 'clean' && matrix.mode != 'coverage'
  + uses: hendrikmuhs/ccache-action@v1
  + with:
  + key: bazel-compile-${{ matrix.mode }}
  +
  + - name: Set environment
  + run: |
  + export PATH=/usr/lib/ccache:$PATH
  + command -v g++ clang++
  +
  - name: ${{ matrix.env.mode }} Verible
  run: ./.github/bin/build-and-test.sh
  