DAOS-17751 test: DO NOT LAND D_POST_INIT/INCR experiment

[kccain]

Initial exercise just with 12_server_ec8p2gx subtest (and a higher Test-repeat amount).

Skip-unit-tests: true Skip-fault-injection-test: true Skip-test-rpms: true Skip-test-el-8.6--rpms: true Skip-test-el-8.6-rpms: true Test-tag: test_ec_online_rebuild_mdtest Test-provider: ofi+verbs Test-repeat: 30

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[bot]]

Ticket title is 'erasurecode/online_rebuild_mdtest.py:EcodOnlineRebuildMdtest.test_ec_online_rebuild_mdtest - test timeout waiting for rebuild' Status is 'In Progress' Labels: '2.6.4rc3,ci_2.6_daily,ci_master_daily,pr_test,scrubbed_2.8' https://daosio.atlassian.net/browse/DAOS-17751