* fix(caching): convert arg to equivalent kwargs in llm caching handler
prevent unexpected errors
* fix(caching_handler.py): don't pass args to caching
* fix(caching): remove all *args from caching.py
* fix(caching): consistent function signatures + abc method
* test(caching_unit_tests.py): add unit tests for llm caching
ensures coverage for common caching scenarios across different implementations
* refactor(litellm_logging.py): move to using cache key from hidden params instead of regenerating one
* fix(router.py): drop redis password requirement
* fix(proxy_server.py): fix faulty slack alerting check
* fix(langfuse.py): avoid copying functions/thread lock objects in metadata
fixes metadata copy error when parent otel span in metadata
* test: update test
