chore(file_utils): fix reportIncompatibleMethodOverride lints

This check is currently turned off in our `basic` `typeCheckingMode`
profile, but is enabled in the `standard` profile.

Things done here:

- matched the signature of `__exit__` and `seekable` to `mmap`'s type
  stub.
- indicate that `seekable` is present in `mmap` in Python 3.13+
- ignored the `seek` method, as we explicitly wanted it to return the
  file position similarly to the standard file api

Error:

    unblob/file_utils.py
      unblob/file_utils.py:70:9 - error: Method "seek" overrides class "mmap" in an incompatible manner
        Return type mismatch: base method returns type "None", override returns type "int"
          "int" is not assignable to "None" (reportIncompatibleMethodOverride)
      unblob/file_utils.py:94:9 - error: Method "__exit__" overrides class "mmap" in an incompatible manner
        Positional parameter count mismatch; base method has 2, but override has 4
        Parameter "args" is missing in override (reportIncompatibleMethodOverride)
      unblob/file_utils.py:103:9 - error: Method "seekable" overrides class "mmap" in an incompatible manner
        Return type mismatch: base method returns type "Literal[True]", override returns type "bool"
          "bool" is not assignable to type "Literal[True]" (reportIncompatibleMethodOverride)

Author: vlaci

unblob/file_utils.py

@@ -8,6 +8,7 @@
 import re
 import shutil
 import struct
+import sys
 import unicodedata
 from collections.abc import Iterable, Iterator
 from pathlib import Path
@@ -67,7 +68,7 @@ def from_path(cls, path: Path, access=mmap.ACCESS_READ):
             m.access = access
             return m
 
-    def seek(self, pos: int, whence: int = os.SEEK_SET) -> int:
+    def seek(self, pos: int, whence: int = os.SEEK_SET) -> int:  # pyright: ignore[reportIncompatibleMethodOverride]
         try:
             super().seek(pos, whence)
         except ValueError as e:
@@ -91,7 +92,7 @@ def size(self) -> int:
     def __enter__(self):
         return self
 
-    def __exit__(self, _exc_type, _exc_val, _exc_tb):
+    def __exit__(self, *args):
         self.close()
 
     def readable(self) -> bool:
@@ -100,8 +101,10 @@ def readable(self) -> bool:
     def writable(self) -> bool:
         return self.access in (mmap.ACCESS_WRITE, mmap.ACCESS_COPY)
 
-    def seekable(self) -> bool:
-        return True  # Memory-mapped files are always seekable
+    if sys.version_info < (3, 13):
+
+        def seekable(self) -> Literal[True]:
+            return True  # Memory-mapped files are always seekable
 
 
 class OffsetFile: