chore(deps): update docker.io/library/mysql docker tag to v9

k8s/invoiceninja/database.yaml

@@ -30,7 +30,7 @@ spec:
     spec:
       containers:
       - name: mysql
-        image: docker.io/library/mysql:8.4.3
+        image: docker.io/library/mysql:9.1.0
         envFrom:
           - secretRef:
               name: mysql

k8s/monica/mysql.yaml

@@ -27,7 +27,7 @@ spec:
         app: mysql
     spec:
       containers:
-      - image: docker.io/library/mysql:5.7
+      - image: docker.io/library/mysql:9.1
         name: mysql
         resources: {}
         ports: