fix(container): update image thanos to v15.7.21

[renovate]

This PR contains the following updates:

Package	Update	Change	OpenSSF
thanos (source)	patch	15.7.19 -> 15.7.21

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Release Notes

bitnami/charts (thanos)

v15.7.21

• [bitnami/thanos] Update index cache config for sharded store gateway (#​28747)

v15.7.20

• [bitnami/thanos] Release 15.7.20 (#​28859) (73a02f4), closes #​28859

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[github-actions]

--- kubernetes/apps/monitoring/thanos/app Kustomization: flux-system/thanos HelmRelease: monitoring/thanos

+++ kubernetes/apps/monitoring/thanos/app Kustomization: flux-system/thanos HelmRelease: monitoring/thanos

@@ -13,13 +13,13 @@

     spec:
       chart: thanos
       sourceRef:
         kind: HelmRepository
         name: bitnami
         namespace: flux-system
-      version: 15.7.19
+      version: 15.7.21
   dependsOn:
   - name: local-path-provisioner
     namespace: kube-system
   - name: redis
     namespace: database
   install: