Revert "Configure rennovate to pinGitHubActionDigests"

It will actually make things more noisy if every new actions/* version then results in a PR. Given they're official github actions I think we can trust them. We can just add the version comment to none official actions

This reverts commit c349a08.

Author: tjenkinson

renovate.json

@@ -1,5 +1,5 @@
 {
-  "extends": ["config:base", "helpers:pinGitHubActionDigests"],
+  "extends": ["config:base"],
   "labels": ["dependencies", "skip-change-log"],
   "prHourlyLimit": 0,
   "prConcurrentLimit": 0,