packed data checksum instabilities with tracks

The test_hlt2_check_packed_data_checksums is showing (new?) instabilities, with various track containers. See e.g.

https://lhcb-nightlies.web.cern.ch/nightly/lhcb-2024-patches/73/Moore/x86_64_v2-el9-gcc13-opt/tests

I can reproduce these instabilities locally, running the test multiple times I get different checksums.

@mveghel @dovombru I am not exactly sure where these are coming from, other than its in the tracking somewhere. It could also be related to other know instabilities we have. Please assign this to whomever you think best suited to take a look.

FYI @msaur