disable mypy for prototype datasets (#7194)

mypy.ini

@@ -37,17 +37,7 @@ allow_redefinition = True
 
 [mypy-torchvision.prototype.datasets.*]
 
-; untyped definitions and calls
-disallow_untyped_defs = True
-
-; None and Optional handling
-no_implicit_optional = True
-
-; warnings
-warn_unused_ignores = True
-
-; miscellaneous strictness flags
-allow_redefinition = True
+ignore_errors = True
 
 [mypy-torchvision.io.image.*]