refactor: unify log format with new logger utility (#5994)

Co-authored-by: sebastienlorber <lorber.sebastien@gmail.com>

packages/docusaurus-plugin-content-docs/src/sidebars/__tests__/generator.test.ts

@@ -57,7 +57,7 @@ describe('DefaultSidebarItemsGenerator', () => {
     expect(sidebarSlice).toEqual([]);
     expect(consoleWarn).toHaveBeenCalledWith(
       expect.stringMatching(
-        /No docs found in dir .: can't auto-generate a sidebar/,
+        /.*\[WARNING\].* No docs found in .*\..*: can't auto-generate a sidebar\..*/,
       ),
     );
   });