pre-commit: Use default plugins rank when checking the doc

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9130>

scripts/git-hooks/pre-commit-python.hook

@@ -125,6 +125,11 @@ def build_cache(builddir, subproject, targets, subdir):
         os.path.join(builddir, f'subprojects/{subproject}/docs/gst_plugins_cache.json'),
     ] + targets
 
+    env = os.environ.copy()
+    try:
+      del env['GST_PLUGIN_FEATURE_RANK']  # Ensure default ranks are applied
+    except KeyError:
+      pass
     subprocess.run(cmd)
 
 class StashManager: