Increase Mocha timeout to 15s for Playwright unit tests

- _after() method has 10s timeout for browser cleanup
- Previous 5s Mocha timeout was causing premature test failures
- 15s timeout gives enough buffer for cleanup to complete
- Fixes 8 failing unit tests with 'Timeout of 5000ms exceeded' in afterEach/after hooks

Author: kobenguyent

.github/workflows/playwright.yml

@@ -65,6 +65,6 @@ jobs:
       - name: run webkit tests
         run: 'BROWSER=webkit node ./bin/codecept.js run -c test/acceptance/codecept.Playwright.js --grep @Playwright --debug'
       - name: run chromium unit tests
-        run: ./node_modules/.bin/mocha test/helper/Playwright_test.js --timeout 5000
+        run: ./node_modules/.bin/mocha test/helper/Playwright_test.js --timeout 15000
       - name: Stop mock server
         run: npm run mock-server:stop