lint: ignore class self annotations (#8492)

## Description

Ignore `self` annotations for class methods. Typing them require `typing-extensions` to use the `Self` type, which is redundant and does not provide new information. Otherwise, the class name is not available when defining methods since it hasn't finished defining, so it requires further hacks to annotate.

Furthermore, [PEP 673](https://peps.python.org/pep-0673) has made self type annotations unnecessary, but is only available on Python 3.11+.

## Checklist
- [ ] I have followed [Sample Guidelines from AUTHORING_GUIDE.MD](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md)
- [ ] README is updated to include [all relevant information](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md#readme-file)
- [ ] **Tests** pass:   `nox -s py-3.9` (see [Test Environment Setup](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md#test-environment-setup))
- [ ] **Lint** pass:   `nox -s lint` (see [Test Environment Setup](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/AUTHORING_GUIDE.md#test-environment-setup))
- [ ] These samples need a new **API enabled** in testing projects to pass (let us know which ones)
- [ ] These samples need a new/updated **env vars** in testing projects set to pass (let us know which ones)
- [ ] Please **merge** this PR for me once it is approved.
- [ ] This sample adds a new sample directory, and I updated the [CODEOWNERS file](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/main/.github/CODEOWNERS) with the codeowners for this sample

Author: davidcavazos

noxfile-template.py

@@ -124,6 +124,7 @@ def _determine_local_import_names(start_dir: str) -> List[str]:
 # Linting with flake8.
 #
 # We ignore the following rules:
+#   ANN101: missing type annotation for self in method
 #   E203: whitespace before ‘:’
 #   E266: too many leading ‘#’ for block comment
 #   E501: line too long
@@ -137,7 +138,7 @@ def _determine_local_import_names(start_dir: str) -> List[str]:
     "--max-complexity=20",
     "--import-order-style=google",
     "--exclude=.nox,.cache,env,lib,generated_pb2,*_pb2.py,*_pb2_grpc.py",
-    "--ignore=E121,E123,E126,E203,E226,E24,E266,E501,E704,W503,W504,I202",
+    "--ignore=ANN101,E121,E123,E126,E203,E226,E24,E266,E501,E704,W503,W504,I202",
     "--max-line-length=88",
 ]