[CI] Add Basic Bazel Checks

Having basic checks (like running buildifier) on the upstream bazel
files would be helpful for contributors maintaining the bazel build. Add
basic checks (currently just buildifier) to a workflow that runs
whenever the bazel build files change.

Author: boomanaiden154

.github/workflows/bazel-checks.yml

@@ -0,0 +1,30 @@
+name: Bazel Checks
+
+permissions:
+  contents: read
+
+on:
+  push:
+    paths:
+      - '.github/workflows/bazel-checks.yml'
+      - 'utils/bazel/**'
+    branches:
+      - main
+  pull_request:
+    paths:
+      - '.github/workflows/bazel-checks.yml'
+      - 'utils/bazel/**'
+
+jobs:
+  buildifier:
+    name: "Buildifier"
+    runs-on: ubuntu-24.04
+    if: github.repository == 'llvm/llvm-project'
+    steps:
+      - name: Fetch LLVM sources
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - name: Setup Buildifier
+        run: |
+          sudo curl -L https://github.com/bazelbuild/buildtools/releases/download/v8.2.1/buildifier-linux-amd64 -o /usr/bin/buildifier
+          sudo chmod +x /usr/bin/buildifier
+          buildifier --mode=check $(find ./utils/bazel -name *BUILD*)