Fix errors on windows

dulwich/porcelain.py

@@ -1351,7 +1351,8 @@ def submodule_update(repo, paths=None, init=False, force=False, errstream=None)
                 os.makedirs(os.path.dirname(submodule_git_dir), exist_ok=True)
 
                 # Clone to the git directory
-                clone(url, submodule_git_dir, bare=True, checkout=False)
+                sub_repo = clone(url, submodule_git_dir, bare=True, checkout=False)
+                sub_repo.close()
 
                 # Create the submodule directory if it doesn't exist
                 if not os.path.exists(submodule_path):

tests/test_porcelain.py

@@ -913,6 +913,7 @@ class CloneTests(PorcelainTestCase):
         sub_repo_path = tempfile.mkdtemp()
         self.addCleanup(shutil.rmtree, sub_repo_path)
         sub_repo = Repo.init(sub_repo_path)
+        self.addCleanup(sub_repo.close)
 
         # Add a file to the submodule repo
         sub_file = os.path.join(sub_repo_path, "subfile.txt")
@@ -3576,6 +3577,7 @@ class SubmoduleTests(PorcelainTestCase):
         sub_repo_path = tempfile.mkdtemp()
         self.addCleanup(shutil.rmtree, sub_repo_path)
         sub_repo = Repo.init(sub_repo_path)
+        self.addCleanup(sub_repo.close)
 
         # Add a file to the submodule repo
         sub_file = os.path.join(sub_repo_path, "test.txt")