Give write permission to validate_pr github workflow (#269)

validate_pr github workflow needs write permission

Author: labkey-tchad

.github/workflows/validate_pr.yml

@@ -11,7 +11,7 @@ on:
       - ready_for_review
 
 permissions:
-  pull-requests: read
+  pull-requests: write
 
 jobs:
   validate_pr: