SRE-3578 test: suppress setgrent() leak

[janekmi]

Found on EL9.7

{
   <insert_a_suppression_name_here>
   Memcheck:Leak
   match-leak-kinds: reachable
   fun:malloc
   fun:nss_files_global_allocate
   fun:__libc_allocate_once_slow
   fun:__nss_files_data_get
   fun:__nss_files_data_setent
   fun:__nss_setent
   fun:setgrent
   fun:test_acl_all_gid_principal_conversion
   obj:/usr/lib64/libcmocka.so.0.7.0
   fun:_cmocka_run_group_tests
   fun:main
}

Test-tag: pr,memcheck

Steps for the author:

• Commit message follows the guidelines.
• Appropriate Features or Test-tag pragmas were used.
• Appropriate Functional Test Stages were run.
• At least two positive code reviews including at least one code owner from each category referenced in the PR.
• Testing is complete. If necessary, forced-landing label added and a reason added in a comment.

After all prior steps are complete:

• Gatekeeper requested (daos-gatekeeper added as a reviewer).

[github-actions]

Errors are Unable to load ticket data
https://daosio.atlassian.net/browse/SRE-3578

[janekmi]

Test status ✅

• https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos/job/PR-17511/1/pipeline-overview/ ✅ (Unit Test + Test - FI)
• https://jenkins-3.daos.hpc.amslabs.hpecorp.net/job/daos-stack/job/daos/job/PR-17511/2/pipeline-overview/ ✅ (FI)