fix: remove legacy Loki PDBs and wait for cleanup

ansible/roles/observability/tasks/main.yml

@@ -79,6 +79,32 @@
   changed_when: false
   failed_when: false
 
+- name: Remove legacy Loki PDBs (if present)
+  command: >-
+    kubectl -n {{ observability_namespace }} delete
+    poddisruptionbudget/loki-memcached-chunks-cache
+    poddisruptionbudget/loki-memcached-results-cache
+    --ignore-not-found=true
+  changed_when: false
+  failed_when: false
+
+- name: Wait for legacy Loki resources to be fully removed
+  shell: >-
+    kubectl -n {{ observability_namespace }} get
+    deployment/loki-gateway
+    statefulset/loki-chunks-cache
+    statefulset/loki-results-cache
+    statefulset/loki-backend
+    statefulset/loki-read
+    statefulset/loki-write
+    2>&1 | grep -q "NotFound\|not found"
+  register: legacy_cleanup
+  retries: 12
+  delay: 5
+  until: legacy_cleanup.rc == 0
+  changed_when: false
+  failed_when: false
+
 - name: Install Loki
   command: >-
     helm upgrade --install loki grafana/loki