Remove distutils.dist.Distribution.announce from the blacklist

[AlexWaygood]

This is no longer necessary following python/typeshed#9795: stubtest now passes for typeshed's setuptools stubs even if the correct default parameter is added to the stdlib stub for distutils.dist.Distribution.announce

[github-actions]

⚠ Diff showing the effect of this PR on how stubdefaulter would alter typeshed's stdlib:

diff --git a/stdlib/distutils/dist.pyi b/stdlib/distutils/dist.pyi
index dfffdc5..e0d2fa5 100644
--- a/stdlib/distutils/dist.pyi
+++ b/stdlib/distutils/dist.pyi
@@ -103,7 +103,7 @@ class Distribution:
     def get_command_packages(self): ...
     def get_command_class(self, command): ...
     def reinitialize_command(self, command, reinit_subcommands: int = 0): ...
-    def announce(self, msg, level: int = ...) -> None: ...
+    def announce(self, msg, level: int = 2) -> None: ...
     def run_commands(self) -> None: ...
     def run_command(self, command) -> None: ...
     def has_pure_modules(self): ...