### Elasticsearch Version

8.4, 8.5, 8.6

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

Darwin

### Problem Description

The shards availability indicator should always be reporting diagnosis when its status is RED/YELLOW.
However, when an index is on a data node that runs out of disk space it will report RED but no diagnosis.

### Steps to Reproduce

Have multi-node cluster where a data (non-master) node that hosts an index runs out of disk space (the index cannot relocate somewhere else).
Call the Health API and the output will be something along these lines:
```
    "shards_availability": {
      "status": "red",
      "symptom": "This cluster has all shards available.",
      "details": {
        "initializing_primaries": 1,
        "started_replicas": 0,
        "initializing_replicas": 0,
        "unassigned_primaries": 0,
        "started_primaries": 1,
        "creating_primaries": 0,
        "unassigned_replicas": 0,
        "restarting_primaries": 0,
        "restarting_replicas": 0
      },
      "impacts": [
        {
          "id": "elasticsearch:health:shards_availability:impact:primary_unassigned",
          "severity": 1,
          "description": "Cannot add data to 1 index [test_index]. Searches might return incomplete results.",
          "impact_areas": [
            "ingest",
            "search"
          ]
        }
      ] 
    }
``` 

### Logs (if relevant)

_No response_
server/src/test/java/org/elasticsearch/cluster/routing/allocation/ShardsAvailabilityHealthIndicatorServiceTests.java
impacts,
            diagnosisList
        );
    }
    private HealthIndicatorResult createExpectedTruncatedResult(HealthStatus status, String symptom, List<HealthIndicatorImpact> impacts) {
        return new HealthIndicatorResult(NAME, status, symptom, HealthIndicatorDetails.EMPTY, impacts, emptyList());
    }
    private static ClusterState createClusterStateWith(List<IndexRoutingTable> indexRoutes, List<NodeShutdown> nodeShutdowns) {
        List<IndexMetadata> indices = indexRoutes.stream()
            .map(
                table -> IndexMetadata.builder(table.getIndex().getName())
                    .settings(Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build())
                    .numberOfShards(1)
                    .numberOfReplicas(table.size() - 1)
                    .build()
            )
            .collect(Collectors.toList());
        return createClusterStateWith(indices, indexRoutes, nodeShutdowns, List.of());
    }
    private static List<IndexMetadata> createIndexMetadataForIndexNameToPriorityMap(Map<String, Integer> indexNameToPriorityMap) {
        List<IndexMetadata> indexMetadataList = new ArrayList<>();
        if (indexNameToPriorityMap != null) {
            for (Map.Entry<String, Integer> indexNameToPriority : indexNameToPriorityMap.entrySet()) {
                String indexName = indexNameToPriority.getKey();
                IndexMetadata.Builder indexMetadataBuilder = new IndexMetadata.Builder(indexName);
                Settings settings = Settings.builder()
                    .put(IndexMetadata.SETTING_PRIORITY, indexNameToPriority.getValue())
                    .put(IndexMetadata.INDEX_NUMBER_OF_SHARDS_SETTING.getKey(), 1)
                    .put(IndexMetadata.INDEX_NUMBER_OF_REPLICAS_SETTING.getKey(), 1)
                    .put(IndexMetadata.SETTING_INDEX_VERSION_CREATED.getKey(), Version.CURRENT)