unmute test (#122603)

Backports the following commits to 8.17:

unmute test (#122592)

Author: drempapis

muted-tests.yml

@@ -228,9 +228,6 @@ tests:
 - class: org.elasticsearch.xpack.restart.CoreFullClusterRestartIT
   method: testSnapshotRestore {cluster=UPGRADED}
   issue: https://github.com/elastic/elasticsearch/issues/111799
-- class: org.elasticsearch.backwards.MixedClusterClientYamlTestSuiteIT
-  method: test {p0=search/380_sort_segments_on_timestamp/Test that index segments are NOT sorted on timestamp field when @timestamp field is dynamically added}
-  issue: https://github.com/elastic/elasticsearch/issues/116221
 - class: org.elasticsearch.xpack.esql.qa.multi_node.EsqlSpecIT
   method: test {categorize.Categorize SYNC}
   issue: https://github.com/elastic/elasticsearch/issues/113054