Behat UI does not work on Drupal 10.3 because of Symfony Process incompatibility

Problem/Motivation

When executing the tests on the Behat UI page, with everything set up correctly, you get a message :

Status message
sh: exec: line 0: cd /var/www/html: not found

Which happens because of the use of Symfony Process which does not allow to CD into a directory.
We should use CWD constructor parameter instead.

Also, the list of commands passed to Symfony Process do not work even after this above fix.
To make it work, we need to split each option into its own line.

Also, the ProcessFailedException used in the try-catch is missing a using statement, making it useless.
We need to add the using statement for the class to load and the try-catch block to be effective.

Proposed resolution

Update the code to use Symfony Process properly.