feat: Add support for python 3.11

chore: Update gapic-generator-python to v1.8.0
PiperOrigin-RevId: 500768693

Author: Google APIs

WORKSPACE

@@ -322,7 +322,7 @@ load("@rules_python//python:pip.bzl", "pip_install")
 
 pip_install()
 
-_gapic_generator_python_version = "1.7.1"
+_gapic_generator_python_version = "1.8.0"
 
 http_archive(
     name = "gapic_generator_python",