revert changing localhost:3001 address

The problem trying to fix is that while initially the course material creates and uses the endpoint 'http://localhost:3001/api/testing/reset', when it refers to using baseUrl it uses as an example the route 'http://localhost:5173/api/tests/reset', which is never used in the course material.
As the course first mentions to "replace all the addresses in the tests from http://localhost:3001/api/... to http://localhost:5173/api/...", it makes sense to use as an example the route 'http://localhost:5173/api/testing/reset'. For this reason, I suggest to change only /tests/ to /testing/ as this might lead to confusion.

Author: jordijs

src/content/5/en/part5d.md

@@ -952,7 +952,7 @@ All the commands in the tests that use the application url, e.g.
 
 ```js
 await page.goto('http://localhost:5173')
-await page.post('http://localhost:3001/api/testing/reset')
+await page.post('http://localhost:5173/api/testing/reset')
 ```
 
 can be transformed into: