### 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
String featureDataStreamName = ".test-ds-feature";
        IndexMetadata backingIndex = createBackingIndex(featureDataStreamName, 1).build();
        List<IndexMetadata> indexMetadataList = List.of(
            IndexMetadata.builder(".feature-index")
                .settings(Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build())
                .numberOfShards(1)
                .numberOfReplicas(0)
                .build(),
            IndexMetadata.builder("regular-index")
                .settings(Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build())
                .numberOfShards(1)
                .numberOfReplicas(0)
                .build(),
            backingIndex
        );
        Metadata.Builder metadataBuilder = Metadata.builder();
        Map<String, IndexMetadata> indexMetadataMap = new HashMap<>();
        for (IndexMetadata indexMetadata : indexMetadataList) {
            indexMetadataMap.put(indexMetadata.getIndex().getName(), indexMetadata);
        }
        metadataBuilder.indices(indexMetadataMap);
        metadataBuilder.put(newInstance(featureDataStreamName, List.of(backingIndex.getIndex())));
        Metadata metadata = metadataBuilder.build();
        {
            List<Diagnosis.Resource> affectedResources = ShardAllocationStatus.getRestoreFromSnapshotAffectedResources(
                metadata,
                getSystemIndices(featureDataStreamName, ".test-ds-*", ".feature-*"),
                Set.of(backingIndex.getIndex().getName(), ".feature-index", "regular-index"),
                10
            );