Chore: update sync-repo-settings.yaml (#10320)

Removing requirement to have branches up-to-date with main, to accelerate merging PRs. Merge conflicts will still be checked. 

This has been reviewed with Python leads, and we can revert it at any time if needed.

Author: kweinmeister

.github/sync-repo-settings.yaml

@@ -39,7 +39,7 @@ branchProtectionRules:
   # Defaults to `false`
   requiresCodeOwnerReviews: true
   # Require up to date branches
-  requiresStrictStatusChecks: true
+  requiresStrictStatusChecks: false
   # List of required status check contexts that must pass for commits to be accepted to matching branches.
   requiredStatusCheckContexts:
     - "Kokoro CI - Lint"