Add stubs for gevent (#10527)

stubs/gevent/METADATA.toml

@@ -0,0 +1,13 @@
+version = "23.9.*"
+upstream_repository = "https://github.com/gevent/gevent"
+requires = ["types-greenlet", "types-psutil"]
+requires_python = ">=3.8"
+
+[tool.stubtest]
+# Run stubtest on all platforms, since there is some platform specific stuff
+# especially in the stdlib module replacement
+platforms = ["linux", "darwin", "win32"]
+# for testing the ffi loop implementations on all platforms
+stubtest_requirements = ["cffi", "dnspython"]
+apt_dependencies = ["libev4", "libev-dev", "libuv1", "libuv1-dev"]
+brew_dependencies = ["libev", "libuv"]