Verify that the apache logs are clean of PHP 8.1 notices/warnings/errors

Important note to developers: This is considered to be e FINAL task within the PHP X.Y issues, and better if it's executed once the upstream branches are already passing both PHPUnit and Behat runs. Only that way the findings here will be useful.

Once we get behat passing, it's time to inspect web server logs to see if there is anything there that has not been detected by the runs.

Usually we get both the logs from a js and non-js run and go looking to them. Ensure they are runs which PHP versions is the one being fixed in the Epic. Older ones aren't meaningful for this issue.

See for example MDL-76064 to know how to clean the logs and focus on the important bits and, also, how to be able to know (by times) which the problematic scenario is.