FIX Update phpunit.xml.dist

[lekoala]

Description

Running tests currently give warnings. This seems fairly easy to fix so I did it :-)

Manual testing steps

No more warnings when running tests

Issues

#11546

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[GuySartorelli]

Explicitly listing each item isn't maintainable - we will innevitably forget to add new directories here when we create them.

[lekoala]

then the other way is to move test files into one folder per test suite that can run in parallel

using "exclude" is not really maintainable either since it's deprecated