add filter_* functions to _pygit2.pyi

Author: DinhHuy2010

pygit2/_pygit2.pyi

@@ -1,6 +1,8 @@
 from io import IOBase
 from typing import Any, Callable, Iterator, Literal, Optional, TypeAlias, overload
 
+from pygit2.filter import Filter
+
 from . import Index
 from .enums import (
     ApplyLocation,
@@ -822,5 +824,9 @@ def init_file_backend(path: str, flags: int = 0) -> object: ...
 def option(opt: Option, *args: Any) -> None: ...
 def reference_is_valid_name(refname: str) -> bool: ...
 def tree_entry_cmp(a: Object, b: Object) -> int: ...
+def filter_register(
+    name: str, filter_cls: type[Filter], priority: int = GIT_FILTER_DRIVER_PRIORITY
+) -> None: ...
+def filter_unregister(name: str) -> None: ...
 
 _cache_enums: Callable[..., None]