MAINT: fixes to comply with pyproject-metadata 0.9.0 type annotations

Author: dnicolodi

mesonpy/__init__.py

@@ -246,7 +246,7 @@ def _validate_name(name: str) -> str:
         return name
 
     @classmethod
-    def from_pyproject(
+    def from_pyproject(  # type: ignore[override]
         cls,
         data: Mapping[str, Any],
         project_dir: Path = os.path.curdir,
@@ -367,7 +367,7 @@ def _libs_dir(self) -> str:
     @property
     def _license_file(self) -> Optional[pathlib.Path]:
         license_ = self._metadata.license
-        if license_:
+        if license_ and isinstance(license_, pyproject_metadata.License):
             return license_.file
         return None