Alerting: Skip sanitizing labels when sending alerts to the remote Alertmanager (#96251)

* Alerting: Skip sanitizing labels when sending alerts to the remote Alertmanager

* fix drone image name

scripts/drone/services/services.star

@@ -57,7 +57,7 @@ def integration_test_services():
             "name": "mimir_backend",
             "image": images["mimir"],
             "environment": {},
-            "commands": ["/bin/mimir -target=backend -alertmanager.grafana-alertmanager-compatibility-enabled"],
+            "commands": ["/bin/mimir -target=backend -alertmanager.grafana-alertmanager-compatibility-enabled -alertmanager.utf8-strict-mode-enabled"],
         },
         {
             "name": "redis",

scripts/drone/utils/images.star

@@ -22,7 +22,7 @@ images = {
     "plugins_slack": "plugins/slack",
     "python": "python:3.8",
     "postgres_alpine": "postgres:12.3-alpine",
-    "mimir": "grafana/mimir-alpine:r304-3872ccb",
+    "mimir": "grafana/mimir-alpine:r316-55f47f8",
     "mysql5": "mysql:5.7.39",
     "mysql8": "mysql:8.0.32",
     "redis_alpine": "redis:6.2.11-alpine",