test: fix flakiness in TestKprobeMatchParentBinaries

[ethical-buddy]

Fixes

Description

TestKprobeMatchParentBinaries was asserting on the exported ProcessKprobe.Parent binary, but that
is not the field used by the matchParentBinaries selector in the exec-without-clone path.

For same-process execs, the selector matches against the previous binary stored in tg_parents_bin,
while the exported Parent field is resolved separately from the real parent process. That made the
test validate the wrong observable and could fail even when selector behavior was correct.

This change keeps the test intent but makes the assertion direct and deterministic:

• run one matching shell and one non-matching shell against different files
• assert that the expected fd_install event is emitted for the matching case
• assert that no corresponding event is emitted for the non-matching case

It also restores option.Config.ParentsMapEnabled with cleanup to avoid leaking global test state.

Changelog

  pkg/sensors/tracing: fix `TestKprobeMatchParentBinaries` to assert selector behavior directly 

[FedeDP]

Ehy thanks for this PR!
It seems like the modified tests are now failing in CI; can you please take a look?