### Elasticsearch Version

8.8.1+ but probably all versions

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

cloud

### Problem Description

This is a follow-up of [#97370](https://github.com/elastic/elasticsearch/issues/97370). 

In a case where disk spaces are reaching limits, if ILM suddenly tries to move a lot of hot shards to cold/frozen shards, it can tip the cluster health to RED because a lot of cold/frozen shards may be created and stay unassigned as long as there is not enough disk space. However, this is not a suitable indicator for service unavailability, since the data is still safely in the respective hot shards that are becoming cold/frozen, and will remain there until the cold/frozen shards are assigned so that searches can still search them.

Thus the [Health Report API](https://www.elastic.co/guide/en/elasticsearch/reference/8.8/health-api.html) should not return RED for unassigned cold/frozen shards of ILM moves.

### Steps to Reproduce

In a case where disk spaces are reaching limits, if ILM suddenly tries to move a lot of hot shards to cold/frozen shards, it can tip the cluster health to RED because a lot of cold/frozen shards may be created and stay unassigned (as long as there is not enough disk space).

### Logs (if relevant)

_No response_
x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java
builder.endObject();
                                }
                                {
                                    builder.startObject("to");
                                    builder.field("type", "long");
                                    builder.endObject();
                                }
                                builder.endObject();
                            }
                            builder.endObject();
                        }
                        builder.endObject();
                    }
                    builder.endObject();
                }
                builder.endObject();
            }
            return builder;
        } catch (IOException e) {
            throw new UncheckedIOException("Failed to build " + SNAPSHOT_BLOB_CACHE_INDEX + " index mappings", e);
        }
    }
    @Override
    public void close() throws IOException {
        Releasables.close(frozenCacheService.get());
    }
    /**
     * Allows to inject the {@link CacheService} instance to transport actions
     */
    public static final class CacheServiceSupplier implements Supplier<CacheService> {