Temporary workaround for tests on 3.9 & 3.10

Author: AA-Turner

pep_sphinx_extensions/pep_zero_generator/pep_index_generator.py

@@ -19,6 +19,7 @@
 
 import json
 import os
+import sys
 from pathlib import Path
 from typing import TYPE_CHECKING
 
@@ -75,5 +76,6 @@ def create_pep_zero(app: Sphinx, env: BuildEnvironment, docnames: list[str]) ->
 
     write_peps_json(peps, Path(app.outdir))
 
-    release_cycle = create_release_cycle()
-    app.outdir.joinpath('release-cycle.json').write_text(release_cycle, encoding="utf-8")
+    if sys.version_info >= (3, 11):
+        release_cycle = create_release_cycle()
+        app.outdir.joinpath('release-cycle.json').write_text(release_cycle, encoding="utf-8")