Update pkg_resources-stubs for use in pytype_test (#9747)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

stubs/setuptools/@tests/stubtest_allowlist.txt

@@ -2,7 +2,6 @@ pkg_resources.Distribution.__cmp__
 pkg_resources.Distribution.activate
 pkg_resources.Distribution.get_entry_map
 pkg_resources.EggMetadata.__init__
-pkg_resources.EggProvider.__init__
 pkg_resources.Environment.best_match
 pkg_resources.Environment.obtain
 pkg_resources.FileMetadata.__init__
@@ -13,12 +12,10 @@ pkg_resources.IMetadataProvider.metadata_isdir
 pkg_resources.IMetadataProvider.metadata_listdir
 pkg_resources.IMetadataProvider.run_script
 pkg_resources.IResourceManager
-pkg_resources.NullProvider.__init__
 pkg_resources.Requirement.__init__
 pkg_resources.WorkingSet.find_plugins
 pkg_resources.WorkingSet.resolve
 pkg_resources.WorkingSet.subscribe
-pkg_resources.ZipProvider.__init__
 pkg_resources.declare_namespace
 pkg_resources.fixup_namespace_packages
 pkg_resources.get_entry_map
@@ -26,6 +23,10 @@ pkg_resources.get_provider
 pkg_resources.split_sections
 pkg_resources.to_filename
 
+# Is always set in __init__
+pkg_resources.PathMetadata.egg_info
+pkg_resources.EggMetadata.loader
+
 # Uncomment once ignore_missing_stub is turned off
 # # Not supported by typeshed
 # setuptools.py34compat