### 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/main/java/org/elasticsearch/cluster/routing/allocation/ShardsAvailabilityHealthIndicatorService.java
}
        /**
         * Returns the diagnosis for unassigned primary and replica shards.
         * @param verbose true if the diagnosis should be generated, false if they should be omitted.
         * @param maxAffectedResourcesCount the max number of affected resources to be returned as part of the diagnosis
         * @return The diagnoses list the indicator identified. Alternatively, an empty list if none were found or verbose is false.
         */
        public List<Diagnosis> getDiagnosis(boolean verbose, int maxAffectedResourcesCount) {
            if (verbose) {
                Map<Diagnosis.Definition, Set<String>> diagnosisToAffectedIndices = new HashMap<>(primaries.diagnosisDefinitions);
                replicas.diagnosisDefinitions.forEach((diagnosisDef, indicesWithReplicasUnassigned) -> {
                    Set<String> indicesWithPrimariesUnassigned = diagnosisToAffectedIndices.get(diagnosisDef);
                    if (indicesWithPrimariesUnassigned == null) {
                        diagnosisToAffectedIndices.put(diagnosisDef, indicesWithReplicasUnassigned);
                    } else {
                        indicesWithPrimariesUnassigned.addAll(indicesWithReplicasUnassigned);
                    }
                });
                if (diagnosisToAffectedIndices.isEmpty()) {
                    return List.of();
                } else {
                    return diagnosisToAffectedIndices.entrySet().stream().map(e -> {
                        List<Diagnosis.Resource> affectedResources = new ArrayList<>(1);
                        if (e.getKey().equals(ACTION_RESTORE_FROM_SNAPSHOT)) {
                            Set<String> restoreFromSnapshotIndices = e.getValue();
                            if (restoreFromSnapshotIndices != null && restoreFromSnapshotIndices.isEmpty() == false) {
                                affectedResources = getRestoreFromSnapshotAffectedResources(
                                    clusterMetadata,
                                    systemIndices,
                                    restoreFromSnapshotIndices,