Add trailing slash to jest configs for consistency

- https://gitlab.com/gitlab-org/gitlab/-/merge_requests/135631#note_1632249105

jest.config.contract.js

 module.exports = () => {
   return {
     modulePaths: ['<rootDir>/spec/contracts/consumer/node_modules/'],
-    roots: ['spec/contracts/consumer', 'ee/spec/contracts/consumer'],
+    roots: ['spec/contracts/consumer/', 'ee/spec/contracts/consumer/'],
   };
 };

jest.config.js

@@ -10,9 +10,9 @@ if (IS_JH && fs.existsSync('./jh/jest.config.js')) {
 } else {
   module.exports = {
     ...baseConfig('spec/frontend', {
-      roots: ['<rootDir>/spec/frontend'],
-      rootsEE: ['<rootDir>/ee/spec/frontend'],
-      rootsJH: ['<rootDir>/jh/spec/frontend'],
+      roots: ['<rootDir>/spec/frontend/'],
+      rootsEE: ['<rootDir>/ee/spec/frontend/'],
+      rootsJH: ['<rootDir>/jh/spec/frontend/'],
     }),
   };
 }

jest.config.scripts.js

@@ -2,7 +2,7 @@ const baseConfig = require('./jest.config.base');
 
 module.exports = {
   ...baseConfig('spec/frontend', {
-    roots: ['<rootDir>/scripts/lib', '<rootDir>/spec/frontend'],
+    roots: ['<rootDir>/scripts/lib/', '<rootDir>/spec/frontend/'],
   }),
   testMatch: [],
 };