chore(deps): update postgres docker tag to v18

| datasource | package  | from | to |
| ---------- | -------- | ---- | -- |
| docker     | postgres | 17   | 18 |

Author: renovate[bot]

compose.production.yaml

@@ -22,7 +22,7 @@ services:
   tux-postgres:
     container_name: tux-postgres
     hostname: tux-postgres
-    image: postgres:17-alpine@sha256:ff4ccc02b97e0ebb6b328ef9ff92522f95586f83be6801896b615088defc8ad2
+    image: postgres:18-alpine@sha256:b40d931bd0e7ce6eecc59a5a6ac3b3c04a01e559750e73e7086b6dbd7f8bf545
     restart: unless-stopped
     environment:
       POSTGRES_DB: ${POSTGRES_DB:-tuxdb}

compose.yaml

@@ -19,7 +19,7 @@ services:
   tux-postgres:
     container_name: tux-postgres
     hostname: tux-postgres
-    image: postgres:17-alpine@sha256:ff4ccc02b97e0ebb6b328ef9ff92522f95586f83be6801896b615088defc8ad2
+    image: postgres:18-alpine@sha256:b40d931bd0e7ce6eecc59a5a6ac3b3c04a01e559750e73e7086b6dbd7f8bf545
     restart: 'no'
     environment:
       POSTGRES_DB: ${POSTGRES_DB:-tuxdb}