Remove Compose file version declaration

docker/stacks/ddclient/ddclient.yml

@@ -1,5 +1,3 @@
-version: "3.7"
-
 services:
    ddclient:
       image: lscr.io/linuxserver/ddclient

docker/stacks/nextcloud/nextcloud.yml

@@ -1,5 +1,3 @@
-version: "3.7"
-
 services:
    nextcloud-cache:
       image: redis

docker/stacks/swag/swag.yml

@@ -1,5 +1,3 @@
-version: "3.7"
-
 services:
    swag:
       image: lscr.io/linuxserver/swag

docker/stacks/watchtower/watchtower.yml

@@ -1,5 +1,3 @@
-version: '3.7'
-
 services:
    watchtower:
       image: containrrr/watchtower

docker/stacks/wireguard/wireguard.yml

@@ -1,5 +1,3 @@
-version: "3.7"
-
 services:
    wireguard:
       image: lscr.io/linuxserver/wireguard