Mute org.elasticsearch.upgrades.IndexingIT testIndexing #135407

muted-tests.yml

@@ -654,6 +654,9 @@ tests:
 - class: org.elasticsearch.upgrades.DataStreamsUpgradeIT
   method: testDataStreamValidationDoesNotBreakUpgrade
   issue: https://github.com/elastic/elasticsearch/issues/135406
+- class: org.elasticsearch.upgrades.IndexingIT
+  method: testIndexing
+  issue: https://github.com/elastic/elasticsearch/issues/135407
 
 # Examples:
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