[`Setting.versionSetting`](https://github.com/elastic/elasticsearch/blob/0652a5915586abbcdfdfffa91a391740f0147752/server/src/main/java/org/elasticsearch/common/settings/Setting.java#L1275) (only used by index compatibility setting) does not use the `Validator` passed in - its just discarded. Looks like it's been like this since it was introduced by https://github.com/elastic/elasticsearch/pull/83264 in 8.2.0.

Enabling this causes some tests to fail. Enabling this may cause problems for indexes that have a wonky setting already applied.
server/src/main/java/org/elasticsearch/common/settings/Setting.java
* given key is part of the settings group.
     * @see #isGroupSetting()
     */
    public final boolean match(String toTest) {
        return key.match(toTest);
    }
    @Override
    public final XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
        builder.startObject();
        builder.field("key", getKey());
        builder.enumSet("properties", properties);
        builder.field("is_group_setting", isGroupSetting());
        builder.field("default", defaultValue.apply(Settings.EMPTY));
        builder.endObject();
        return builder;
    }
    @Override
    public String toString() {
        return Strings.toString(this, true, true);
    }
    /**
     * Returns the value for this setting but falls back to the second provided settings object
     */
    public final T get(Settings primary, Settings secondary) {
        if (exists(primary)) {
            return get(primary);
        }
        if (exists(secondary)) {
            return get(secondary);
        }