ci(apache): mpm fails to find libgcc-s1 in spread tests

[lczyk]

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4. The event MPM appears to cause segfaults when run as part of the spread test suite in Github Actions, because Apache claims libgcc_s.so.1 must be installed for pthread_exit to work, however this library is definitely present in the chroot. When we run Apache locally in our own containers, this does not seem to occur, so we are unable to determine what is causing the event MPM to fail in as part of the spread test suite in Github Actions.

Originally posted by @norrisjeremy in #532 (comment)

also discussed here:

• feat(26.04): add apache2 slices #839 (comment)