appdirs: improve annotation for appauthor argument (#9876)

Fix: Missing annotation for appauthor argument

According to the appdirs doc string and code [1], the appauthor argument in all functions supports False as argument value to skip insertion of author directories.

[1] https://github.com/ActiveState/appdirs/blob/master/appdirs.py#L52

Author: Jakob-Stadler

stubs/appdirs/appdirs.pyi

@@ -6,25 +6,25 @@ unicode = str
 system: str
 
 def user_data_dir(
-    appname: str | None = ..., appauthor: str | None = ..., version: str | None = ..., roaming: bool = ...
+    appname: str | None = ..., appauthor: str | Literal[False] | None = ..., version: str | None = ..., roaming: bool = ...
 ) -> str: ...
 def site_data_dir(
-    appname: str | None = ..., appauthor: str | None = ..., version: str | None = ..., multipath: bool = ...
+    appname: str | None = ..., appauthor: str | Literal[False] | None = ..., version: str | None = ..., multipath: bool = ...
 ) -> str: ...
 def user_config_dir(
-    appname: str | None = ..., appauthor: str | None = ..., version: str | None = ..., roaming: bool = ...
+    appname: str | None = ..., appauthor: str | Literal[False] | None = ..., version: str | None = ..., roaming: bool = ...
 ) -> str: ...
 def site_config_dir(
-    appname: str | None = ..., appauthor: str | None = ..., version: str | None = ..., multipath: bool = ...
+    appname: str | None = ..., appauthor: str | Literal[False] | None = ..., version: str | None = ..., multipath: bool = ...
 ) -> str: ...
 def user_cache_dir(
-    appname: str | None = ..., appauthor: str | None = ..., version: str | None = ..., opinion: bool = ...
+    appname: str | None = ..., appauthor: str | Literal[False] | None = ..., version: str | None = ..., opinion: bool = ...
 ) -> str: ...
 def user_state_dir(
-    appname: str | None = ..., appauthor: str | None = ..., version: str | None = ..., roaming: bool = ...
+    appname: str | None = ..., appauthor: str | Literal[False] | None = ..., version: str | None = ..., roaming: bool = ...
 ) -> str: ...
 def user_log_dir(
-    appname: str | None = ..., appauthor: str | None = ..., version: str | None = ..., opinion: bool = ...
+    appname: str | None = ..., appauthor: str | Literal[False] | None = ..., version: str | None = ..., opinion: bool = ...
 ) -> str: ...
 
 class AppDirs:
@@ -36,7 +36,7 @@ class AppDirs:
     def __init__(
         self,
         appname: str | None = ...,
-        appauthor: str | None = ...,
+        appauthor: str | Literal[False] | None = ...,
         version: str | None = ...,
         roaming: bool = ...,
         multipath: bool = ...,