Once https://github.com/elastic/elasticsearch/issues/98503 is done, we can use our minimum version numbers in the SystemIndexMappingUpdate service instead of the old `Version` types. Mappings will be updated for a system index when all nodes have a matching descriptor mappings version for a system index, but this version is greater than what's stored in the mappings metadata.
server/src/test/java/org/elasticsearch/cluster/ClusterStateTests.java
"shard" : 0,
                              "index" : "index",
                              "allocation_id" : {
                                "id" : "%s"
                              },
                              "relocation_failure_info" : {
                                "failed_attempts" : 0
                              }
                            }
                          ],
                          "nodeId1" : [ ]
                        }
                      }
                    }""",
                ephemeralId,
                Version.CURRENT,
                IndexVersion.MINIMUM_COMPATIBLE,
                IndexVersion.current(),
                TransportVersion.current(),
                IndexVersion.current(),
                IndexVersion.current(),
                allocationId,
                allocationId
            ),
            Strings.toString(builder)
        );
    }
    public void testToXContent_FlatSettingFalse_ReduceMappingTrue() throws IOException {
        Map<String, String> mapParams = new HashMap<>() {
            {