Maintenance: Update dependency rubocop-graphql to v1.5.1

Gemfile.lock

@@ -555,7 +555,7 @@ GEM
     rubocop-faker (1.1.0)
       faker (>= 2.12.0)
       rubocop (>= 0.82.0)
-    rubocop-graphql (1.5.0)
+    rubocop-graphql (1.5.1)
       rubocop (>= 0.90, < 2)
     rubocop-inflector (0.2.1)
       activesupport