chore(deps): update postgres:18.6-alpine docker digest to 77f5851 (#310)

k8s/infra/postgres.yaml

@@ -53,7 +53,7 @@ spec:
     spec:
       containers:
       - name: postgres
-        image: postgres:18.6-alpine@sha256:6c538e7206ea40ff740ef27883529390a690b6ead6ba96b44c67a9f7c638e8fd
+        image: postgres:18.6-alpine@sha256:77f585114c32fbca283dc835b0596f4e52b51b4c6662d7810b2f4084f60a1873
         args:
         - -c
         - shared_buffers=384MB