fix typo (#8460)

Author: jugmac00

src/_pytest/tmpdir.py

@@ -134,7 +134,7 @@ def getbasetemp(self) -> Path:
 @final
 @attr.s(init=False)
 class TempdirFactory:
-    """Backward comptibility wrapper that implements :class:``_pytest.compat.LEGACY_PATH``
+    """Backward compatibility wrapper that implements :class:``_pytest.compat.LEGACY_PATH``
     for :class:``TempPathFactory``."""
 
     _tmppath_factory = attr.ib(type=TempPathFactory)