Rename job, use consistent formatting

Author: LostLuma

.github/workflows/signoff.yaml

@@ -1,10 +1,12 @@
 name: validate-signoff
 on:
   pull_request:
-    types: [opened, edited]
+    types:
+      - opened
+      - edited
 
 jobs:
-  build:
+  validate:
     runs-on: ubuntu-latest
     steps:
       - name: checkout repository