Cherry-pick of the #36011 merge (six commits) as a single unit.
(cherry picked from commit c898d341c0)
Backport adaptation for stable/1.91.x:
- litellm/proxy/auth/auth_utils.py: took only the `extract_nested_form_metadata`
import this commit adds. The neighbouring
`LITELLM_PASS_THROUGH_ENDPOINT_MARKER` import is context in the upstream diff,
not an addition; that symbol does not exist on this line and is referenced
nowhere here, so importing it would have broken module import.
- litellm/proxy/health_endpoints/_health_endpoints.py: kept this line's `typing`
import idiom and added `Final` and `Mapping` there, rather than taking
upstream's `from collections.abc import Iterable, Mapping`. This line never
took staging's collections.abc migration and still sources `Iterable` from
`typing`.
- litellm/proxy/litellm_pre_call_utils.py: added `Final` to the `typing` import,
required by the extracted `reject_url_valued_destination`. Upstream already
had it from a later lint pass that is not on this line.
- tests/test_litellm/proxy/auth/test_auth_utils.py: kept this commit's own
`TestIsRequestBodySafeChecksBracketNotationMetadata` and omitted the
staging-prior `TestGetKeyTagRateLimits`, whose subject `get_key_tag_rpm_limit`
does not exist on this line.
49995ba9ce