feature: use SKIP_CI_PREFIX variable

.github/workflows/main.yaml

@@ -3,6 +3,7 @@ name: Main
 on:
   push:
     branches:
+      - main
       - master
 
 env:
@@ -10,7 +11,7 @@ env:
 
 jobs:
   build:
-    if: "contains(github.event.head_commit.message, '[CI]:') != true"
+    if: "contains(github.event.head_commit.message, vars.SKIP_CI_PREFIX) != true"
 
     runs-on: docker
     container:
@@ -47,4 +48,4 @@ jobs:
       - name: Push changelog
         uses: stefanzweifel/git-auto-commit-action@v5
         with:
-          commit_message: "[CI]: Push updated changelog"
+          commit_message: "${{ vars.SKIP_CI_PREFIX }} Push updated changelog"