[Tests] Removes skipped tests in YAML runner

Author: picandocodigo

elasticsearch-api/spec/yaml-test-runner/run.rb

@@ -85,5 +85,4 @@ def serverless?
 Elasticsearch::Tests::Downloader::run(tests_path, branch)
 
 runner = Elasticsearch::Tests::TestRunner.new(CLIENT, tests_path, logger)
-runner.add_tests_to_skip('knn_search.yml') # TODO: Extract into file
 runner.run(ENV['SINGLE_TEST'] || [])