chore(deps): update prom/prometheus docker tag to v3.13.1 (#304)

Co-authored-by: renovate-gh-app-micxer[bot] <202420550+renovate-gh-app-micxer[bot]@users.noreply.github.com>

Author: renovate-gh-app-micxer[bot]

defaults/main.yml

@@ -41,7 +41,7 @@ homestack_nextcloud_redis_version: 8.8.0
 homestack_monitoring_active: true
 homestack_monitoring_base_domain: example.com
 # renovate: image=prom/prometheus
-homestack_monitoring_prometheus_image_version: v3.12.0
+homestack_monitoring_prometheus_image_version: v3.13.1
 # homestack_monitoring_prometheus_base_path: ""  # must be set
 # homestack_monitoring_prometheus_basic_auth_user: ""  # must be set
 # homestack_monitoring_prometheus_basic_auth_password: ""  # must be set