workflows: Rename the "invalid" label to "not_on_github"

Use a more appropriate label name.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

.github/workflows/close-invalid-bot.yaml

@@ -1,10 +1,10 @@
-# Close issues marked as invalid
-name: "Close issues marked as invalid"
+# Close issues marked as not_on_github
+name: "Close issues marked as not_on_github"
 on:
   schedule:
     - cron: '0 */6 * * *'
 jobs:
-  close_invalid:
+  close_issues:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/github-script@v3
@@ -14,7 +14,7 @@ jobs:
               owner: context.repo.owner,
               repo: context.repo.repo,
               state: 'open',
-              labels: 'invalid',
+              labels: 'not_on_github',
               per_page: 100,
               page: 1
             });

.github/workflows/invalid-label-bot.yaml

@@ -1,5 +1,5 @@
-# Add a comment to github issues marked with the invalid label
-name: "Add comment to issues marked invalid"
+# Add a comment to github issues marked with the not_on_github label
+name: "Add comment to issues marked not_on_github"
 on:
   issues:
       types: [labeled]
@@ -11,7 +11,7 @@ jobs:
         with:
           github-token: ${{secrets.GITHUB_TOKEN}}
           script: |
-            if (context.payload.label.name != "invalid")
+            if (context.payload.label.name != "not_on_github")
               return;
             msg = "It looks like this ticket is a request for help"
                 + " (or similar)."