Give auto-merge label workflow permission to add labels to issues (#18078)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

.github/workflows/add_label_automerge.yml

 name: Add label on auto-merge enabled
 permissions:
-    issues: write
+    pull-requests: write
 on:
     pull_request_target:
         types:

.github/workflows/reminder_comment.yml

 name: PR Reminder Comment Bot
 permissions:
-  issues: write
+  pull-requests: write
 on:
   pull_request_target:
     types: [opened]