fix(tests): scope submodule fixture to module, restore env after tests

Author: TheGreatApollyon

tests/test_vcs.py

@@ -205,17 +205,20 @@ def test_remote_clone_recovers_from_corrupt_mirror(
     assert Path(dst2, "README.md").read_text() == "hello world"
 
 
-@pytest.fixture(scope="session", autouse=True)
+@pytest.fixture(scope="module", autouse=True)
 def allow_file_submodules() -> None:
     """Allow the fixture repos below to be used as submodules.
 
     Since Git 2.38.1 the file protocol is blocked for submodules by default
     (see GHSA-3wp6-j8xr-qw85), so local submodules require this setting. Set
     it via the environment so it also applies to Copier's own subprocesses.
     """
-    local.env["GIT_CONFIG_COUNT"] = "1"
-    local.env["GIT_CONFIG_KEY_0"] = "protocol.file.allow"
-    local.env["GIT_CONFIG_VALUE_0"] = "always"
+    with local.env(
+        GIT_CONFIG_COUNT="1",
+        GIT_CONFIG_KEY_0="protocol.file.allow",
+        GIT_CONFIG_VALUE_0="always",
+    ):
+        yield
 
 
 def test_remote_clone_submodule_with_moved_url(