feat(database): use itemized list in extra volume for certificate

template/stacks/forgejo/forgejo-server/values.yaml

@@ -31,7 +31,6 @@ extraVolumeMounts:
   - mountPath: /etc/ssl/forgejo/postgres.pem
     name: postgres-cert-volume
     readOnly: true
-    subPath: postgres.pem
 
 extraVolumes:
   - name: elasticsearch-cert-volume
@@ -41,6 +40,9 @@ extraVolumes:
   - name: postgres-cert-volume
     secret:
       secretName: otc-rds-tls-ca-cert
+      items:
+      - key: postgres.pem
+        path: postgres.pem
 
 gitea:
   additionalConfigFromEnvs: