curses is not available on Windows (#6749)

stdlib/curses/textpad.pyi

@@ -1,11 +1,12 @@
-from _curses import _CursesWindow
+import sys
 from typing import Callable
 
-def rectangle(win: _CursesWindow, uly: int, ulx: int, lry: int, lrx: int) -> None: ...
-
-class Textbox:
-    stripspaces: bool
-    def __init__(self, win: _CursesWindow, insert_mode: bool = ...) -> None: ...
-    def edit(self, validate: Callable[[int], int] | None = ...) -> str: ...
-    def do_command(self, ch: str | int) -> None: ...
-    def gather(self) -> str: ...
+if sys.platform != "win32":
+    from _curses import _CursesWindow
+    def rectangle(win: _CursesWindow, uly: int, ulx: int, lry: int, lrx: int) -> None: ...
+    class Textbox:
+        stripspaces: bool
+        def __init__(self, win: _CursesWindow, insert_mode: bool = ...) -> None: ...
+        def edit(self, validate: Callable[[int], int] | None = ...) -> str: ...
+        def do_command(self, ch: str | int) -> None: ...
+        def gather(self) -> str: ...