chore: upgrade to gapic-generator-python 0.44.0

chore: add GAPIC metadata
feat: add support for self-signed JWT
PiperOrigin-RevId: 370525906

WORKSPACE

@@ -278,8 +278,8 @@ pip_repositories()
 
 http_archive(
     name = "gapic_generator_python",
-    strip_prefix = "gapic-generator-python-0.43.3",
-    urls = ["https://github.com/googleapis/gapic-generator-python/archive/v0.43.3.zip"],
+    strip_prefix = "gapic-generator-python-0.44.0",
+    urls = ["https://github.com/googleapis/gapic-generator-python/archive/v0.44.0.zip"],
 )
 
 load(