Update min version to 2_19_1

* since 2.19 version has been merged:
  opensearch-project#17420

Signed-off-by: Asim Mahmood <asim.seng@gmail.com>

Author: asimmahmood1

server/src/main/java/org/opensearch/search/aggregations/metrics/CardinalityAggregationBuilder.java

@@ -116,7 +116,7 @@ public CardinalityAggregationBuilder(StreamInput in) throws IOException {
         if (in.readBoolean()) {
             precisionThreshold = in.readLong();
         }
-        if (in.getVersion().onOrAfter(Version.V_2_20_0)) {
+        if (in.getVersion().onOrAfter(Version.V_2_19_1)) {
             executionHint = in.readOptionalString();
         }
     }
@@ -133,7 +133,7 @@ protected void innerWriteTo(StreamOutput out) throws IOException {
         if (hasPrecisionThreshold) {
             out.writeLong(precisionThreshold);
         }
-        if (out.getVersion().onOrAfter(Version.V_2_20_0)) {
+        if (out.getVersion().onOrAfter(Version.V_2_19_1)) {
             out.writeOptionalString(executionHint);
         }
     }