move varibles to relevant task

Taskfile.yml

@@ -4,21 +4,21 @@
 
 version: '3'
 
-vars:
-  RELEASE:
-    sh: svu next
-  BRANCH:
-    sh: git branch --show-current
-  COMMIT:
-    sh: git rev-parse --short --verify {{.BRANCH}}
-
 tasks:
 
   release:
     desc: Create and publish an new release
-    prompt: Create new release {{.RELEASE}} from {{.COMMIT}}@{{.BRANCH}}?
+    vars:
+      RELEASE:
+        sh: svu next
+      BRANCH:
+        sh: git branch --show-current
+      COMMIT:
+        sh: git rev-parse --short --verify {{.BRANCH}}
     preconditions:
       - sh: test "{{.BRANCH}}" == "main"
+        msg: "You must be on the main branch to release"
+    prompt: Create new release {{.RELEASE}} from {{.COMMIT}}@{{.BRANCH}}?
     cmds:
       - git tag {{.RELEASE}}
       - git push