fix dulwich warning ls-remote result dict (#421)

Author: shcheklein

pyproject.toml

@@ -23,7 +23,7 @@ requires-python = ">=3.9"
 dynamic = ["version"]
 dependencies = [
     "gitpython>3",
-    "dulwich>=0.22.1",
+    "dulwich>=0.23.1",
     "pygit2>=1.14.0",
     "pygtrie>=2.3.2",
     "fsspec[tqdm]>=2024.2.0",

src/scmrepo/git/backend/dulwich/__init__.py

@@ -990,7 +990,7 @@ def ls_remote(url: str) -> dict[str, str]:
     from dulwich.client import HTTPUnauthorized
 
     try:
-        refs = porcelain.ls_remote(url)
+        refs = porcelain.ls_remote(url).refs
         return {os.fsdecode(ref): sha.decode("ascii") for ref, sha in refs.items()}
     except HTTPUnauthorized as exc:
         raise AuthError(url) from exc