feat: use build.yml directly from gardenlinux

Author: nkraetzschmar

.github/actions/setup

@@ -0,0 +1 @@
+../../gardenlinux/.github/actions/setup

.github/actions/setup/action.yml

@@ -24,7 +24,7 @@ jobs:
         run: echo "VERSION=$(cat VERSION)" >> $GITHUB_OUTPUT
   build:
     needs: [set_version]
-    uses: ./.github/workflows/build.yml
+    uses: gardenlinux/gardenlinux/.github/workflows/build.yml@fcbff6e3816474fa4b2ce27eef0513d3354fb81a
     with:
       version: ${{ needs.set_version.outputs.VERSION }}
       arch: '["amd64"]'