Add django.utils.http.content_disposition_header. (#1448)

Author: alexmv

django-stubs/utils/http.pyi

@@ -43,3 +43,4 @@ def parse_qsl(
     separator: str = ...,
 ) -> list[tuple[str, str]]: ...
 def escape_leading_slashes(url: str) -> str: ...
+def content_disposition_header(as_attachment: bool, filename: str) -> str | None: ...