fix: bump APP_INI_VERSION to v23 (app.ini.tmpl changed in the forgejo removal)

Docker Swarm configs are IMMUTABLE — only labels can be updated. The config is
named ${STACK_NAME}_app_ini_${APP_INI_VERSION}, so when app.ini.tmpl's rendered
content changes the version suffix MUST be bumped, otherwise abra tries to mutate
the existing object and the deploy aborts:

  FATA failed to update config <stack>_app_ini_v22: Error response from daemon:
  rpc error: code = InvalidArgument desc = only updates to Labels are allowed

'BREAKING CHANGE: remove forgejo' (6a0339d) edited app.ini.tmpl —

  -{{ if or (eq (env "FORGE") "forgejo") (eq (env "GITEA_LFS_START_SERVER") "true") }}
  +{{ if (eq (env "GITEA_LFS_START_SERVER") "true") }}

— but left APP_INI_VERSION at v22 (unchanged since the LFS commit 357926f), and
3.6.2+1.27.1-rootless shipped that way. Every existing deployment upgrading ACROSS
the forgejo removal therefore fails at 'initialising deployment'; reproduced on a
live 3.6.1+1.26.2-rootless -> 3.6.2+1.27.1-rootless upgrade.

Bumping to v23 makes Swarm create a NEW config object instead of mutating v22. The
orphaned v22 object can be pruned after the rollout. Only app.ini.tmpl changed, so
DOCKER_SETUP_SH_VERSION and PG_BACKUP_VERSION stay put.

Note: cc-ci's upgrade tier did not catch this because it resolved the upgrade base
to main-tip, which ALREADY contains the forgejo removal — base and head then render
identical app.ini and no config update is attempted. Real deployments upgrade from
the last published RELEASE (3.6.1+1.26.2), which is where the break appears.

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
@@ -87,7 +87,7 @@ 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.${STACK_NAME}.version=3.6.3+1.27.1-rootless
+        - coop-cloud.${STACK_NAME}.version=3.6.2+1.27.1-rootless
 
 
 networks: