Add Github action to run Bazel tests for every PR

This will ensure that all pull requests must pass all Bazel tests in the
repository. Merging the pull request will be blocked until the tests are
passing, and will re-run each time the pull request is synchronized or
updated.
diff --git a/.github/workflows/run-bazel-tests.yml b/.github/workflows/run-bazel-tests.yml
new file mode 100644
index 0000000..71331a6
--- /dev/null
+++ b/.github/workflows/run-bazel-tests.yml
@@ -0,0 +1,14 @@
+name: Run Bazel tests
+on: [pull_request]
+
+jobs:
+  run-bazel-tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: bazel-contrib/setup-bazel@0.8.5
+        with:
+          bazelisk-cache: true
+          disk-cache: ${{ github.workflow }}
+          repository-cache: true
+      - run: bazel test ...