### Elasticsearch Version

master

### Installed Plugins

N/A

### Java Version

_bundled_

### OS Version

N/A

### Problem Description

@arteam [observed](https://github.com/elastic/elasticsearch/pull/83221/files#r795474431) that `static record` is redundant, records are apparently implicitly static. I think we should make sure that Checkstyle picks this up rather than needing human involvement.

### Steps to Reproduce

Mark a record declaration as `static` and observe that `./gradlew precommit` still passes.

### Logs (if relevant)

_No response_
server/src/main/java/org/elasticsearch/cluster/routing/IndexRouting.java
private final boolean routingRequired;
        IdAndRoutingOnly(IndexMetadata metadata) {
            super(metadata);
            MappingMetadata mapping = metadata.mapping();
            this.routingRequired = mapping == null ? false : mapping.routingRequired();
        }
        protected abstract int shardId(String id, @Nullable String routing);
        @Override
        public void process(IndexRequest indexRequest) {
            if ("".equals(indexRequest.id())) {
                throw new IllegalArgumentException("if _id is specified it must not be empty");
            }
            
            if (indexRequest.id() == null) {
                indexRequest.autoGenerateId();
            }
        }
        @Override
        public int indexShard(String id, @Nullable String routing, XContentType sourceType, BytesReference source) {
            if (id == null) {