Update the version checks around ip_range bucket keys, now that the change was backported.

rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/40_range.yml

@@ -213,8 +213,8 @@ setup:
 ---
 "IP Range Key Generation":
   - skip:
-     version: " - 6.99.99"
-     reason: "Before 7.0.0, ip_range did not always generate bucket keys (see #21045)."
+     version: " - 6.3.99"
+     reason: "Before 6.4.0, ip_range did not always generate bucket keys (see #21045)."
 
   - do:
       search:

server/src/main/java/org/elasticsearch/search/aggregations/bucket/range/InternalBinaryRange.java

@@ -74,7 +74,7 @@ public final class InternalBinaryRange
         }
 
         private static Bucket createFromStream(StreamInput in, DocValueFormat format, boolean keyed) throws IOException {
-            String key = in.getVersion().onOrAfter(Version.V_7_0_0_alpha1)
+            String key = in.getVersion().onOrAfter(Version.V_6_4_0)
                 ? in.readString()
                 : in.readOptionalString();
 
@@ -88,7 +88,7 @@ public final class InternalBinaryRange
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
-            if (out.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            if (out.getVersion().onOrAfter(Version.V_6_4_0)) {
                 out.writeString(key);
             } else {
                 out.writeOptionalString(key);