Unmute OldRepositoryAccessIT testOldRepoAccess / testOldSourceOnlyRepoAccess (elastic#134624)

This has been muted for a long time now, unmuting to get some pulse on
whether this test generally still works and if the infrequent failures
persist.

Author: cbuescher

muted-tests.yml

@@ -120,12 +120,6 @@ tests:
 - class: org.elasticsearch.xpack.security.QueryableReservedRolesIT
   method: testConfiguredReservedRolesAfterClosingAndOpeningIndex
   issue: https://github.com/elastic/elasticsearch/issues/120127
-- class: org.elasticsearch.oldrepos.OldRepositoryAccessIT
-  method: testOldRepoAccess
-  issue: https://github.com/elastic/elasticsearch/issues/120148
-- class: org.elasticsearch.oldrepos.OldRepositoryAccessIT
-  method: testOldSourceOnlyRepoAccess
-  issue: https://github.com/elastic/elasticsearch/issues/120080
 - class: org.elasticsearch.xpack.ccr.FollowIndexSecurityIT
   method: testCleanShardFollowTaskAfterDeleteFollower
   issue: https://github.com/elastic/elasticsearch/issues/120339