Add GitLab error to known errors when the SSH key is read-only (#12311)

ref:
-
https://read-the-docs.sentry.io/issues/6721034615/events/cbc8f641367a4d55b1b3edc190730b48/?query=
-
https://read-the-docs.sentry.io/issues/6721316212/?project=161479&query=&referrer=issue-stream&stream_index=10

Author: stsewd

readthedocs/vcs_support/backends/git.py

@@ -174,7 +174,10 @@ def has_ssh_key_with_write_access(self) -> bool:
            to ensure that no commands controled by the user are run.
         """
         remote_name = "rtd-test-ssh-key"
-        ssh_url = re.sub("https?://github.com/", "[email protected]:", self.project.repo, 1)
+        ssh_url = self.project.repo
+        if ssh_url.startswith("http"):
+            parsed_url = urlparse(ssh_url)
+            ssh_url = f"git@{parsed_url.netloc}:{parsed_url.path.lstrip('/')}"
 
         try:
             cmd = ["git", "remote", "add", remote_name, ssh_url]
@@ -215,6 +218,8 @@ def has_ssh_key_with_write_access(self) -> bool:
                 # but since the key can't be used from the builders,
                 # it should be safe to return False.
                 "ERROR: The repository owner has an IP allow list enabled",
+                # Gitlab:
+                "ERROR: This deploy key does not have write access to this project.",
             ]
             for pattern in errors_read_access_only:
                 if pattern in stderr: