Crash SIGSEGV from vault.(*PolicyStore).getACLView when fetching metrics

[ebuildy]

Describe the bug

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x3410a44]
failed to find message
goroutine 13121591 [running]:
github.com/hashicorp/vault/vault.(*PolicyStore).getACLView(...)
	/home/runner/work/vault/vault/vault/policy_store_util.go:23
github.com/hashicorp/vault/vault.(*PolicyStore).policiesByNamespace(0x10fc6830?, {0xb8c5270?, 0xc01d05f0b0?}, 0x8422760?, 0x10ff06e0?)
	/home/runner/work/vault/vault/vault/policy_store.go:688 +0x24
github.com/hashicorp/vault/vault.(*PolicyStore).policiesByNamespaces(0xb8c5318?, {0xb8c5270, 0xc01d05f0b0}, 0x1d55ce00?, {0xc01d55ce20, 0x1, 0xc01b8da1e0?})
	/home/runner/work/vault/vault/vault/policy_store.go:722 +0xf6
github.com/hashicorp/vault/vault.(*Core).configuredPoliciesGaugeCollector(0xc003454800, {0xb8c5318, 0xc01bbc61c0})
	/home/runner/work/vault/vault/vault/core_metrics.go:596 +0x193
github.com/hashicorp/vault/helper/metricsutil.(*GaugeCollectionProcess).collectAndFilterGauges(0xc01de41e00)
	/home/runner/work/vault/vault/helper/metricsutil/gauge_process.go:186 +0x155
github.com/hashicorp/vault/helper/metricsutil.(*GaugeCollectionProcess).Run(0xc01de41e00)
	/home/runner/work/vault/vault/helper/metricsutil/gauge_process.go:270 +0x8a
created by github.com/hashicorp/vault/vault.(*Core).emitMetricsActiveNode in goroutine 13121571
	/home/runner/work/vault/vault/vault/core_metrics.go:335 +0xdf6

To Reproduce

Dont find how to reproduce it, vault runs during a few days then crash.

Expected behavior
Dont crash

Environment:

• Vault Server Version (retrieve with vault status): 1.15.4
• Vault CLI Version (retrieve with vault version): 1.15.4
• Server Operating System/Architecture: Azure Kubernetes Service, official Helm chart
• Backend: mysql

Vault server configuration file(s):

ui = true
disable_mlock = true
default_lease_ttl = "24h"
max_lease_ttl = "24h"

listener "tcp" {
  tls_disable = "true"
  address = "[::]:8200"
  cluster_address = "[::]:8201"
  # Enable unauthenticated metrics access (necessary for Prometheus Operator)
  telemetry {
    unauthenticated_metrics_access = true
  }
}
storage "mysql" {
  address = "XXXX.mysql.database.azure.com"
  database = "vault"
  username = "XXXX"
  password = "XXXXX"
  tls_ca_file = "/trust-bundles/all/trust-bundle.pem"
  ha_enabled = "true"
}

service_registration "kubernetes" {}

telemetry {
  prometheus_retention_time = "74h"
  disable_hostname = true
}

Additional context
Add any other context about the problem here.