Tweak patterned_text_feature_flag_enabled ff. (elastic#130637)

Adjusted version from 9.2.0 to 9.1.0, given that it has been backported to the 9.1 branch.

 Relates to elastic#130633

Author: martijnvg

test/test-clusters/src/main/java/org/elasticsearch/test/cluster/FeatureFlag.java

@@ -22,7 +22,7 @@ public enum FeatureFlag {
     USE_LUCENE101_POSTINGS_FORMAT("es.use_lucene101_postings_format_feature_flag_enabled=true", Version.fromString("9.1.0"), null),
     IVF_FORMAT("es.ivf_format_feature_flag_enabled=true", Version.fromString("9.1.0"), null),
     LOGS_STREAM("es.logs_stream_feature_flag_enabled=true", Version.fromString("9.1.0"), null),
-    PATTERNED_TEXT("es.patterned_text_feature_flag_enabled=true", Version.fromString("9.2.0"), null);
+    PATTERNED_TEXT("es.patterned_text_feature_flag_enabled=true", Version.fromString("9.1.0"), null);
 
     public final String systemProperty;
     public final Version from;