Log Message:
py-google-api-core: update to 2.15.0.

Features

    Add support for Python 3.12 (#557) (091b4f1)
    Add type annotations to wrapped grpc calls (#554) (fc12b40)
    Add universe_domain argument to ClientOptions (3069ef4)
    Introduce compatibility with native namespace packages (#561) (bd82827)

Bug Fixes

    Fix regression in bidi causing Thread-ConsumeBidirectionalStream caught \ 
unexpected exception  and will exit (#562) (40c8ae0)
    Replace deprecated datetime.datetime.utcnow() (#552) (448923a), closes #540