Add Bazel cache (#2059)

Author: wsmoses

.bazelrc

@@ -1,3 +1,8 @@
+# Public read-only cache
+common:public_cache --remote_cache="https://storage.googleapis.com/enzyme-presubmit-bazel-cache/" --remote_upload_local_results=false
+
+# Cache pushes are limited to Enzyme's CI system.
+common:public_cache_push --config=public_cache --remote_upload_local_results=true --google_default_credentials
 
 common --noenable_bzlmod
 

.github/workflows/build.yml

@@ -107,6 +107,7 @@ jobs:
             BAZEL_FLAGS="${BAZEL_FLAGS} --test_env=JAX_PLATFORMS=cpu"
           fi
 
+          BAZEL_FLAGS="${BAZEL_FLAGS} --config=public_cache_push"
           echo "BAZEL_FLAGS=${BAZEL_FLAGS}" >> "${GITHUB_ENV}"
       - uses: actions/checkout@v6
       - uses: bazel-contrib/setup-bazel@0.16.0