fix(clean): add missing cleanup (#4023)

datahub-graphql-core/build.gradle

@@ -41,6 +41,10 @@ graphqlCodegen {
     ]
 }
 
+clean {
+    delete 'mainGeneratedGraphQL'
+}
+
 tasks.withType(Checkstyle) {
     exclude "**/generated/**"
 }

datahub-web-react/build.gradle

@@ -65,6 +65,8 @@ clean {
   delete 'tmp'
   delete 'build'
   delete 'just'
+  delete 'src/types.generated.ts'
+  delete 'src/graphql/*.generated.ts'
 }
 
 configurations {