- Fix issues with async functionality per issue #1045.

- Update GoogleAdsClient.get_services method to expose async service …

…clients.

- Add support for Application Default Credentials (ADC) functionality.

- Add annotations to google/ads/googleads/*.py files.
- Add minor unit test improvements.

Add support for Python 3.14

Upgrade min version of "nox"

Release Google Ads API version 28.1.0

Create version of google-ads-python 28.0.0 that's only compatible with

Python 3.8.

Temporarily remove incompatibility with Python 3.8

- Google Ads API v21_0 release.

- Updated to Google Ads API v19_0 and v20_0 to include EU political advertising changes.
- Remove Google Ads API v18.
- Add deprecation warnings for Python 3.9 users.
- Add type annotations to all examples.
- Add unit tests covering some examples.

- Google Ads API v20_0 release.

- Remove Google Ads API v17.
- Add example for generating audience insights.
- Add example for creating demand gen campaign.