chore(images): pin service image updates

Replace floating service images with reviewable tags or digests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

vaultwarden/k8s/vaultwarden.yaml

@@ -27,7 +27,7 @@ spec:
     spec:
       containers:
         - name: vaultwarden
-          image: vaultwarden/server:latest
+          image: vaultwarden/server:1.37.3
           ports:
             - containerPort: 80
           envFrom: