chore: Update to gapic-generator-python 1.6.0

Google APIs · copybara-github · commit da380c77bb87 · 2022-11-09T13:08:23.000-08:00
feat(python): Add typing to proto.Message based class attributes

feat(python): Snippetgen handling of repeated enum field

PiperOrigin-RevId: 487326846
diff --git a/WORKSPACE b/WORKSPACE
@@ -292,7 +292,7 @@ load("@rules_python//python:pip.bzl", "pip_install")
 
 pip_install()
 
-_gapic_generator_python_version = "1.5.0"
+_gapic_generator_python_version = "1.6.0"
 
 http_archive(
     name = "gapic_generator_python",
