ci: fetch clang-tidy package in fix-sync (#50724)

fix-sync re-downloads llvm-build on macOS/Windows with the base clang
and objdump packages, but not clang-tidy. A local gclient sync pulls
clang-tidy (checkout_clang_tidy=True in DEPS), so CI's llvm-build tree
diverges from a local one. siso hashes the toolchain as action input,
so cache-only local runs against the CI-populated RBE cache miss.

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Samuel Attard <sattard@anthropic.com>

.github/actions/fix-sync/action.yml

@@ -27,6 +27,7 @@ runs:
         python3 src/tools/clang/scripts/update.py
         # Refs https://chromium-review.googlesource.com/c/chromium/src/+/6667681
         python3 src/tools/clang/scripts/update.py --package objdump
+        python3 src/tools/clang/scripts/update.py --package clang-tidy
     - name: Fix esbuild
       if: ${{ inputs.target-platform != 'linux' }}
       uses: ./src/electron/.github/actions/cipd-install