chore: update shared files

Automated update of shared files from the social-core repository, see
https://github.com/python-social-auth/.github/blob/main/repo-sync.py

Author: nijel

.github/renovate.json

@@ -2,7 +2,8 @@
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": [
     "config:recommended",
-    ":dependencyDashboard"
+    ":dependencyDashboard",
+    "helpers:pinGitHubActionDigests"
   ],
   "automerge": true,
   "automergeType": "pr",

.pre-commit-config.yaml

@@ -52,3 +52,7 @@ repos:
   - id: codespell
     additional_dependencies:
     - tomli
+- repo: https://github.com/rhysd/actionlint
+  rev: v1.7.7
+  hooks:
+  - id: actionlint