Adopt a policy of building against latest AGP to surface deprecation warnings early

Investigate running a dedicated CI job against the newest (even pre-release) AGP version so deprecations and best-practice changes surface continuously, rather than being discovered in bulk during major-version bump projects (getsentry/sentry-java#5777/650/651).

Start by reviewing the repository's CI configuration and the related issues getsentry/sentry-java#5777, #650, and #651. The issue names no specific files or tests; done means a dedicated CI job builds against the newest, including pre-release, AGP version and surfaces deprecation or best-practice warnings continuously.

Written by the indexing model from the issue text.