feat(ci): nightly job to completely clean up bazel caches

.github/workflows/bazel.yaml

@@ -5,6 +5,9 @@ on:
       - 'main'
   pull_request:
   merge_group:
+  schedule:
+    # * is a special character in YAML so you have to quote this string
+    - cron:  '30 1 * * *'
 jobs:
   bazel:
     runs-on: ubuntu-22.04
@@ -28,6 +31,9 @@ jobs:
           key: ${{ runner.os }}-bazel-${{ hashFiles('.bazelversion', '.bazelrc', 'WORKSPACE', 'WORKSPACE.bazel', 'MODULE.bazel', 'Cargo.Bazel.lock') }}
           restore-keys: |
             ${{ runner.os }}-bazel-
+      - name: If running on schedule (at night) and on main, completely delete bazel cache
+        if: "${{github.event.schedule == '30 1 * * *' && github.ref == 'refs/heads/main'}}"
+        run: sudo rm -rf ~/.cache/bazel/*
       - name: Set GIT_HASH variable
         run: |
           # Set GIT_HASH variable based on the type of GitHub reference