handle importlib-metadata deprecation

importlib-metadata promises that it will start raising KeyError for
missing values, rather than returning None

src/poetry/repositories/installed_repository.py

@@ -257,9 +257,8 @@ def load(cls, env: Env, with_dependencies: bool = False) -> InstalledRepository:
                 if path in skipped:
                     continue
 
-                try:
-                    name = canonicalize_name(distribution.metadata["name"])
-                except TypeError:
+                name = distribution.metadata.get("name")  # type: ignore[attr-defined]
+                if name is None:
                     logger.warning(
                         (
                             "Project environment contains an invalid distribution"
@@ -271,6 +270,8 @@ def load(cls, env: Env, with_dependencies: bool = False) -> InstalledRepository:
                     skipped.add(path)
                     continue
 
+                name = canonicalize_name(distribution.metadata["name"])
+
                 if name in seen:
                     continue