DX: remove docs/_relink_references.py script (#237)

Use https://pypi.org/project/sphinx-api-relink instead.

src/repoma/check_dev_files/deprecated.py

@@ -1,5 +1,8 @@
 """Remove deprecated linters and formatters."""
 
+import os
+
+from repoma.errors import PrecommitError
 from repoma.utilities import remove_configs, remove_from_gitignore
 from repoma.utilities.executor import Executor
 from repoma.utilities.precommit import remove_precommit_hook
@@ -11,6 +14,8 @@ def remove_deprecated_tools(keep_issue_templates: bool) -> None:
     if not keep_issue_templates:
         executor(_remove_github_issue_templates)
     executor(_remove_markdownlint)
+    for directory in ["docs", "doc"]:
+        executor(_remove_relink_references, directory)
     executor.finalize()
 
 
@@ -35,3 +40,14 @@ def _remove_markdownlint() -> None:
     )
     executor(remove_precommit_hook, "markdownlint")
     executor.finalize()
+
+
+def _remove_relink_references(directory: str) -> None:
+    path = f"{directory}/_relink_references.py"
+    if not os.path.exists(path):
+        return
+    msg = (
+        f"Please remove {path!r} and use https://pypi.org/project/sphinx-api-relink"
+        " instead."
+    )
+    raise PrecommitError(msg)