[prometheus-memcached-exporter] Update dependency prometheus/memcached_exporter to v0.15.4 (#6261)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

charts/prometheus-memcached-exporter/Chart.yaml

@@ -2,9 +2,9 @@ apiVersion: v2
 name: prometheus-memcached-exporter
 description: Prometheus exporter for Memcached metrics
 type: application
-version: 0.4.3
+version: 0.4.4
 # renovate: github=prometheus/memcached_exporter
-appVersion: "v0.15.3"
+appVersion: "v0.15.4"
 home: https://github.com/prometheus/memcached_exporter
 sources:
   - https://github.com/prometheus/memcached_exporter