### 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
IndexMetadata indexMetadata = IndexMetadata.builder("red-index")
            .settings(Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).build())
            .numberOfShards(1)
            .numberOfReplicas(0)
            .build();
        
        var clusterState = createClusterStateWith(
            List.of(indexMetadata),
            List.of(index("red-index", new ShardAllocation(randomNodeId(), UNAVAILABLE, randomFrom(decidersNo(), nodeLeft())))),
            List.of(),
            List.of()
        );
        
        Map<ShardRoutingKey, ShardAllocationDecision> decisionMap = Map.of(
            new ShardRoutingKey("red-index", 0, true),
            new ShardAllocationDecision(
                AllocateUnassignedDecision.fromDecision(
                    Decision.NO,
                    null,
                    List.of(
                        new NodeAllocationResult(
                            new DiscoveryNode(randomNodeId(), buildNewFakeTransportAddress(), Version.CURRENT),
                            new Decision.Multi().add(Decision.single(Decision.Type.YES, EnableAllocationDecider.NAME, null))
                                .add(Decision.single(Decision.Type.YES, "data_tier", null))
                                .add(Decision.single(Decision.Type.YES, ShardsLimitAllocationDecider.NAME, null))
                                .add(Decision.single(Decision.Type.YES, FilterAllocationDecider.NAME, null))
                                .add(Decision.single(Decision.Type.YES, SameShardAllocationDecider.NAME, null))
                                .add(Decision.single(Decision.Type.NO, AwarenessAllocationDecider.NAME, null)), 
                            1
                        )