Remove empty __init__ methods (#8816)

stdlib/xml/sax/handler.pyi

@@ -9,7 +9,6 @@ class ErrorHandler:
     def warning(self, exception: BaseException) -> None: ...
 
 class ContentHandler:
-    def __init__(self) -> None: ...
     def setDocumentLocator(self, locator): ...
     def startDocument(self): ...
     def endDocument(self): ...

stdlib/xml/sax/xmlreader.pyi

@@ -1,7 +1,6 @@
 from collections.abc import Mapping
 
 class XMLReader:
-    def __init__(self) -> None: ...
     def parse(self, source): ...
     def getContentHandler(self): ...
     def setContentHandler(self, handler): ...