Delete many redundant method redefinitions (#6877)

stdlib/email/charset.pyi

@@ -17,7 +17,6 @@ class Charset:
     def header_encode(self, string: str) -> str: ...
     def header_encode_lines(self, string: str, maxlengths: Iterator[int]) -> list[str]: ...
     def body_encode(self, string: str) -> str: ...
-    def __str__(self) -> str: ...
     def __eq__(self, other: Any) -> bool: ...
     def __ne__(self, other: Any) -> bool: ...
 

stdlib/email/header.pyi

@@ -13,7 +13,6 @@ class Header:
     ) -> None: ...
     def append(self, s: bytes | str, charset: Charset | str | None = ..., errors: str = ...) -> None: ...
     def encode(self, splitchars: str = ..., maxlinelen: int | None = ..., linesep: str = ...) -> str: ...
-    def __str__(self) -> str: ...
     def __eq__(self, other: Any) -> bool: ...
     def __ne__(self, other: Any) -> bool: ...
 

stdlib/email/headerregistry.pyi

@@ -159,7 +159,6 @@ class Address:
     def __init__(
         self, display_name: str = ..., username: str | None = ..., domain: str | None = ..., addr_spec: str | None = ...
     ) -> None: ...
-    def __str__(self) -> str: ...
 
 class Group:
     @property
@@ -167,4 +166,3 @@ class Group:
     @property
     def addresses(self) -> tuple[Address, ...]: ...
     def __init__(self, display_name: str | None = ..., addresses: Iterable[Address] | None = ...) -> None: ...
-    def __str__(self) -> str: ...

stdlib/email/message.pyi

@@ -17,7 +17,6 @@ class Message:
     preamble: str | None
     epilogue: str | None
     defects: list[MessageDefect]
-    def __str__(self) -> str: ...
     def is_multipart(self) -> bool: ...
     def set_unixfrom(self, unixfrom: str) -> None: ...
     def get_unixfrom(self) -> str | None: ...