infra: vertex integration test creds (#15609)

.github/workflows/_integration_test.yml

@@ -37,6 +37,12 @@ jobs:
         shell: bash
         run: poetry install --with test,test_integration
 
+      - name: 'Authenticate to Google Cloud'
+        id: 'auth'
+        uses: google-github-actions/auth@v2
+        with:
+          credentials_json: '${{ secrets.GOOGLE_CREDENTIALS }}'
+
       - name: Run integration tests
         shell: bash
         env:

.github/workflows/_release.yml

@@ -149,6 +149,12 @@ jobs:
         run: make tests
         working-directory: ${{ inputs.working-directory }}
 
+      - name: 'Authenticate to Google Cloud'
+        id: 'auth'
+        uses: google-github-actions/auth@v2
+        with:
+          credentials_json: '${{ secrets.GOOGLE_CREDENTIALS }}'
+
       - name: Run integration tests
         if: ${{ startsWith(inputs.working-directory, 'libs/partners/') }}
         env: