Re-add .resolve() method to package_resources.Entrypoint (#2385)

Fixes #1463

third_party/3/pkg_resources.pyi

@@ -132,6 +132,7 @@ class EntryPoint:
              installer: Optional[_InstallerType] = ...) -> Any: ...
     def require(self, env: Optional[Environment] = ...,
                 installer: Optional[_InstallerType] = ...) -> None: ...
+    def resolve(self) -> Any: ...
 
 
 def find_distributions(