Add github actions CI

.github/workflows/workflow.yml

@@ -0,0 +1,42 @@
+name: CEL-Policy CI
+run-name: Workflow started by ${{ github.actor }}.
+on:
+  push:
+    branches:
+      - 'main'
+  pull_request:
+    branches:
+      - 'main'
+
+# Cancel previous workflows on the PR when there are multiple fast commits.
+# https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#concurrency
+concurrency:
+    group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
+    cancel-in-progress: true
+
+jobs:
+  Bazel-Build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - run: echo "🎉 The job was automatically triggered by a ${{ github.event_name }} event."
+      - run: echo "🐧 Job is running on a ${{ runner.os }} server!"
+      - run: echo "🔎 The name of your branch is ${{ github.ref }} and your repository is ${{ github.repository }}."
+      - name: Check out repository code
+        uses: actions/checkout@v6
+      - name: Setup Bazel
+        uses: bazel-contrib/setup-bazel@0.18.0
+        with:
+            # Avoid downloading Bazel every time.
+            bazelisk-cache: true
+            # Store build cache per workflow.
+            disk-cache: ${{ github.workflow }}
+            # Share repository cache between workflows.
+            repository-cache: true
+            # Prevent PRs from polluting cache
+            cache-save: ${{ github.event_name != 'pull_request' }}
+      - name: Bazel Output Version
+        run: bazelisk --version
+      - name: Bazel Build
+        run: bazel build ...
+      - run: echo "🍏 This job's status is ${{ job.status }}."