Chore: Enable comma-dangle on ESLint codebase (fixes #7725) (#7906)

Author: not-an-aardvark

index.js

@@ -56,7 +56,7 @@ function formatMessage(message, parentResult) {
         `${type}:`,
         `${msg}`,
         ruleId ? `${ruleId}` : "",
-        sourceCode ? `at ${filePath}:` : `at ${filePath}`,
+        sourceCode ? `at ${filePath}:` : `at ${filePath}`
     ].filter(String).join(" ");
 
     const result = [firstLine];

test.js

@@ -146,7 +146,7 @@ describe("formatter:codeframe", () => {
                 line: 1,
                 column: 7,
                 ruleId: "no-unused-vars"
-            }],
+            }]
         }];
 
         it("should return a string with multiple entries", () => {