Fixing check for xAOD filters

Description of bug

The check introduced in !2857 (merged) and updated in !2910 (merged) is too strict. Apparently the HepMC bug does not affect certain filters, in particular the MET ones and because of https://gitlab.cern.ch/atlas/athena/-/blob/release/23.6.12/Generators/GeneratorFilters/src/MissingEtFilter.cxx?ref_type=tags#L25 it is causing issues.

There are two solutions:

1. fine-tune more (done here, in particular excluding the MET filters and CreatexAODSlimContainers.py from the test)
2. get rid of the test completely

Ewelina was in favour of the 2nd option. @ancuetog @dhirsch should we go with the 2nd option instead?

Changes introduced

Tests

Before

After

Issues resolved

Closes #