### 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
assertThat(
                ACTION_INCREASE_SHARD_LIMIT_CLUSTER_SETTING_LOOKUP.get(tier).getUniqueId(),
                equalTo("elasticsearch:health:shards_availability:diagnosis:increase_shard_limit_cluster_setting:tier:" + tier)
            );
            assertThat(
                ACTION_MIGRATE_TIERS_AWAY_FROM_REQUIRE_DATA_LOOKUP.get(tier).getUniqueId(),
                equalTo("elasticsearch:health:shards_availability:diagnosis:migrate_data_tiers_require_data:tier:" + tier)
            );
            assertThat(
                ACTION_MIGRATE_TIERS_AWAY_FROM_INCLUDE_DATA_LOOKUP.get(tier).getUniqueId(),
                equalTo("elasticsearch:health:shards_availability:diagnosis:migrate_data_tiers_include_data:tier:" + tier)
            );
            assertThat(
                ACTION_INCREASE_TIER_CAPACITY_LOOKUP.get(tier).getUniqueId(),
                equalTo("elasticsearch:health:shards_availability:diagnosis:increase_tier_capacity_for_allocations:tier:" + tier)
            );
        }
    }
    private HealthIndicatorResult createExpectedResult(
        HealthStatus status,
        String symptom,
        Map<String, Object> details,
        List<HealthIndicatorImpact> impacts,
        List<Diagnosis> diagnosisList
    ) {
        return new HealthIndicatorResult(
            NAME,
            status,
            symptom,
            new SimpleHealthIndicatorDetails(addDefaults(details)),