google-genai: bump test deps to latest

google-auth bumped too, new google-genai needs >=2.48.1.

Assisted-by: Claude Opus 4.7 (1M context)
Signed-off-by: Mikhail Basov <Michael.S.Sinclair@protonmail.com>

Author: banlor

instrumentation-genai/opentelemetry-instrumentation-google-genai/tests/requirements.latest.txt

@@ -40,10 +40,10 @@ pytest==7.4.4
 pytest-asyncio==0.21.0
 pytest-vcr==1.0.2
 
-google-auth==2.47.0
+google-auth==2.50.0
 
 google-genai==1.47.0; python_version < "3.10"
-google-genai==1.64.0; python_version >= "3.10"
+google-genai==1.75.0; python_version >= "3.10"
 
 # Install locally from the folder. This path is relative to the
 # root directory, given invocation from "tox" at root level.