chore(python): remove CONTRIBUTING.rst from templates

.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python:latest
-  digest: sha256:023a21377a2a00008057f99f0118edadc30a19d1636a3fee47189ebec2f3921c
-# created: 2025-03-31T16:51:40.130756953Z
+  digest: sha256:710b70faff81151657d89db6e028c23a1051787598c8276bdd8eef25c92da8ab
+# created: 2025-04-10T17:48:54.829145676Z

owlbot.py

@@ -211,48 +211,6 @@ def docfx(session):
     r"Dict[str, str]",
 )
 
-# Add documentation about creating indexes and populating data for system
-# tests.
-assert 1 == s.replace(
-    "CONTRIBUTING.rst",
-    r"""
-\*\*\*\*\*\*\*\*\*\*\*\*\*
-Test Coverage
-\*\*\*\*\*\*\*\*\*\*\*\*\*
-""",
-    """
-- You'll need to create composite
-  `indexes <https://cloud.google.com/datastore/docs/tools/indexconfig>`__
-  with the ``gcloud`` command line
-  `tool <https://developers.google.com/cloud/sdk/gcloud/>`__::
-
-   # Install the app (App Engine Command Line Interface) component.
-   $ gcloud components install app-engine-python
-
-   # Authenticate the gcloud tool with your account.
-   $ GOOGLE_APPLICATION_CREDENTIALS="path/to/app_credentials.json"
-   $ gcloud auth activate-service-account \
-   > --key-file=${GOOGLE_APPLICATION_CREDENTIALS}
-
-   # Create the indexes
-   $ gcloud datastore indexes create tests/system/index.yaml
-
-- You'll also need stored data in your dataset. To populate this data, run::
-
-   $ python tests/system/utils/populate_datastore.py
-
-- If you make a mistake during development (i.e. a failing test that
-  prevents clean-up) you can clear all system test data from your
-  datastore instance via::
-
-   $ python tests/system/utils/clear_datastore.py
-
-*************
-Test Coverage
-*************
-""",
-)
-
 # add type checker nox session
 s.replace(
     "noxfile.py",