chore(deps): update container image bitnami/alertmanager to 0.26.0@9e7e46e by renovate (#18477)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| bitnami/alertmanager | digest | `5779c22` -> `9e7e46e` |

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This PR has been generated by [Renovate
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<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy4yMDMuMyIsInVwZGF0ZWRJblZlciI6IjM3LjIwMy4zIiwidGFyZ2V0QnJhbmNoIjoibWFzdGVyIn0=-->

charts/enterprise/prometheus/Chart.yaml

@@ -50,4 +50,4 @@ sources:
   - https://hub.docker.com/r/bitnami/alertmanager
   - https://quay.io/thanos/thanos
 type: application
-version: 16.7.1
+version: 16.7.2

charts/enterprise/prometheus/values.yaml

@@ -6,7 +6,7 @@ thanosImage:
   tag: v0.34.1@sha256:567346c3f6ff2927c2c6c0daad977b2213f62d45eca54d48afd19e6deb902181
 alertmanagerImage:
   repository: bitnami/alertmanager
-  tag: 0.26.0@sha256:5779c22b78afa1dec3a2f0285ccb1d7077f60b42482cde06a4fe62b539c7229c
+  tag: 0.26.0@sha256:9e7e46e5a8fa16d7c67bcae3fc7fcd96e19958459c6dbee487bf538867a0465c
 global:
   labels: {}
 workload: