Unmute yaml test (#130803)

Unmute yaml test fixed by #130732

Closes #130626, #130661

Author: jimczi

muted-tests.yml

@@ -530,9 +530,6 @@ tests:
 - class: org.elasticsearch.index.engine.ThreadPoolMergeExecutorServiceDiskSpaceTests
   method: testUnavailableBudgetBlocksNewMergeTasksFromStartingExecution
   issue: https://github.com/elastic/elasticsearch/issues/130205
-- class: org.elasticsearch.backwards.MixedClusterClientYamlTestSuiteIT
-  method: test {p0=search.vectors/40_knn_search/Dimensions are dynamically set}
-  issue: https://github.com/elastic/elasticsearch/issues/130626
 - class: org.elasticsearch.search.SearchWithRejectionsIT
   method: testOpenContextsAfterRejections
   issue: https://github.com/elastic/elasticsearch/issues/130821