Revert "Test: mute failing mtermvector rest test"

This reverts commit 5ba0ed9c8f57b954a122a5b364b09da5551118fd as this
test was already fixed by 4c2e0d76f32090c2731a1fa8a8a6b3ede828ccb5.

Closes #36281

rest-api-spec/src/main/resources/rest-api-spec/test/mtermvectors/10_basic.yml

@@ -21,9 +21,7 @@ setup:
 
 ---
 "Basic tests for multi termvector get":
-  - skip:
-      version: "all"
-      reason:  "Test fails in ci see https://github.com/elastic/elasticsearch/issues/36281"
+
   - do:
       mtermvectors:
         "term_statistics" : true