build: update the list of required status check contexts (#404)

Co-authored-by: omair <omairn@google.com>

Author: ohmayr

packages/proto-plus/.github/sync-repo-settings.yaml

@@ -11,12 +11,20 @@ branchProtectionRules:
     - 'unit (3.6, cpp)'
     - 'unit (3.7)'
     - 'unit (3.7, cpp)'
+    - 'unit (3.7, upb)'
     - 'unit (3.8)'
-    - 'unit (3.9, cpp)'
+    - 'unit (3.8, cpp)'
+    - 'unit (3.8, upb)'
     - 'unit (3.9)'
-    - 'unit (3.10, cpp)'
+    - 'unit (3.9, cpp)'
+    - 'unit (3.9, upb)'
     - 'unit (3.10)'
+    - 'unit (3.10, cpp)'
+    - 'unit (3.10, upb)'
     - 'unit (3.11)'
+    - 'unit (3.11, upb)'
+    - 'unit (3.12)'
+    - 'unit (3.12, upb)'
     - cover
     - OwlBot Post Processor
     - 'cla/google'