chore: shorten tests.yaml and enable subtitutions on cloudbuild yaml

Author: kgala2

.cl/cloudbuild.yaml

@@ -20,5 +20,9 @@ steps:
       - -c
       - "4"
       - google.com
+
 options:
+  dynamicSubstitutions: true
+  pool:
+    name: $_POOL_NAME
   logging: CLOUD_LOGGING_ONLY

.github/workflows/tests.yml

@@ -0,0 +1,63 @@
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: tests
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+  schedule:
+    - cron: "0 2 * * *"
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  unit:
+    name: unit tests
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.9", "3.13"]
+      fail-fast: false
+    permissions:
+      contents: read
+      id-token: write
+      issues: write
+      pull-requests: write
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Setup Python ${{ matrix.python-version }}
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install nox
+        run: pip install nox
+
+      - id: auth
+        name: Authenticate to Google Cloud
+        # only needed for Flakybot on periodic (schedule) and continuous (push) events
+        if: ${{ github.event_name == 'schedule' || github.event_name == 'push' }}
+        uses: google-github-actions/auth@71f986410dfbc7added4569d411d040a91dc6935 # v2.1.8
+        with:
+          workload_identity_provider: ${{ vars.PROVIDER_NAME }}
+          service_account: ${{ vars.SERVICE_ACCOUNT }}
+          access_token_lifetime: 600s
+
+      - name: Run tests
+        run: nox -s unit-${{ matrix.python-version }}