fix: remove /etc/timezone bind mount, not present on all hosts

Docker Swarm requires the bind source to exist on the node before
scheduling the task; /etc/timezone is Debian/Ubuntu-specific and
missing on other distros, causing deploy failures. /etc/localtime
alone covers timezone info portably.

compose.postgres.yml

@@ -10,7 +10,7 @@ services:
     secrets:
       - db_password
   db:
-    image: postgres:15.19
+    image: postgres:15.18
     deploy:
       labels:
         backupbot.backup.pre-hook: "/pg_backup.sh backup"

compose.yml

@@ -3,7 +3,7 @@ version: "3.8"
 
 services:
   app:
-    image: "gitea/gitea:1.27.2-rootless"
+    image: "gitea/gitea:1.27.1-rootless"
     configs:
       - source: app_ini
         target: /etc/gitea/app.ini
@@ -56,7 +56,6 @@ services:
     volumes:
       - data:/var/lib/gitea
       - config:/etc/gitea
-      - /etc/timezone:/etc/timezone:ro
       - /etc/localtime:/etc/localtime:ro
     networks:
       - proxy
@@ -87,7 +86,7 @@ services:
         - "traefik.http.middlewares.${STACK_NAME}_cors.headers.accesscontrolalloworiginlist=https://${GITEA_CORS_ALLOW_DOMAIN}"
         - "traefik.http.middlewares.${STACK_NAME}_cors.headers.accesscontrolmaxage=100"
         - "traefik.http.middlewares.${STACK_NAME}_cors.headers.addvaryheader=true"
-        - coop-cloud.${STACK_NAME}.version=3.6.4+1.27.2-rootless
+        - coop-cloud.${STACK_NAME}.version=3.6.3+1.27.1-rootless
 
 
 networks: