do not post comments when locking pull requests (#1799)

.github/workflows/issue-lint.yml

@@ -1,11 +1,11 @@
-name: issues
+name: issue-link
 
 on:
   issues:
     types: [opened]
 
 jobs:
-  issues:
+  issue-link:
     runs-on: ubuntu-latest
 
     steps:

.github/workflows/issue-lock.yml

@@ -33,6 +33,7 @@ jobs:
                 continue;
               }
 
+              if (!issue.pull_request) {
                 await github.rest.issues.createComment({
                   owner,
                   repo,
@@ -40,6 +41,7 @@ jobs:
                   body: 'This issue is being locked automatically because it has been closed for more than 6 months.\n'
                     + 'Please open a new issue in case you encounter a similar problem.',
                 });
+              }
 
               github.rest.issues.lock({
                 owner,