ci: Refactor Ci for new machine

.forgejo/workflows/demo.yaml

@@ -3,21 +3,14 @@ on: [push, pull_request]
 
 jobs:
   build-and-test:
-    runs-on: alpine
+    runs-on: ubuntu-20.04
     
     container:
       image: rust:alpine
 
     steps:
-      - name: Install Git
-        run: apk add --no-cache git
-
       - name: Checkout code
-        env:
-          REPO_TOKEN: ${{ secrets.CHECKOUT_TOKEN }}
-        run: |
-          git clone https://oauth2:${{ env.REPO_TOKEN }}@git.rustprogersteam.ru/${{ github.repository }}.git .
-          git checkout ${{ github.sha }}
+        uses: actions/checkout@v4
 
       - name: Build
         run: cargo build --verbose