ref(transport): Log a warning when dropping envelopes due to rate-limiting

[rwachtler]

:scroll: Description

• Raise the level of an existing log statement which indicated that all envelope items were rate-limited, to SENTRY_LOG_WARN.
• Introduce a new log statement which will log a warning each time an envelope item has been dropped due to an exceeding rate-limit.
• Update clang-formatter to 19.1.2
  • When trying to commit I've got following error:
    • clang-format version mismatch, expected: 19.1.1, but found: 19.1.2. Please run make init to update your local dev tools. This may actually upgrade to a newer version than what is currently recorded in the lockfile; if that happens, please commit the update to the lockfile as well.
    • Tried to resolve via make init, but then followed This may actually upgrade to a newer version than what is currently recorded in the lockfile; if that happens, please commit the update to the lockfile as well.
  • It looks like pre-commit, python and mobile-dev-inc/tap/maestro got updated as well, but since those weren't crucial for the commit, I didn't stage/commit those changes.

:bulb: Motivation and Context

• Fixes #4456

:green_heart: How did you test it?

• Ran SentryHttpTransportTests

See below:

Running all tests in SentryHttpTransportTests

:pencil: Checklist

You have to check all boxes before merging:

• [x] I reviewed the submitted code.
• [ ] I added tests to verify the changes.
• [x] No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• [ ] I updated the docs if needed.
• [x] Review from the native team if needed.
• [x] No breaking change or entry added to the changelog.
• [x] No breaking change for hybrid SDKs or communicated to hybrid SDKs.

:crystal_ball: Next steps

• Let me know if the new log message is specific/descriptive enough, or feel free to suggest an alternative. Thanks!