ci: update build job to only build

.gitea/workflows/gentoo-utils.yml

@@ -86,12 +86,21 @@ jobs:
 
   build:
     runs-on: brutalisk
-    container:
-      image: git.epenguin.net/gentoo-utils/gentoo-utils-gitea:latest
+    env:
+      CC: 'clang'
+      CXX: 'clang++'
     needs: build-oci-image
+    container:
+      image: ${{ vars.REGISTRY_URL }}/${{ gitea.repository }}:${{ needs.build-oci-image.outputs.image_tag }}
     steps:
       - name: Checkout repo
         uses: actions/checkout@v5
 
       - name: build and check
-        run: ./check.sh
+        run: |
+          echo $USER
+          echo "CC=$CC"
+          echo "CXX=$CXX"
+          source /etc/profile
+          meson setup -Dfuzz=enabled -Dtests=enabled -Dbuildtype=debugoptimized -Ddocs=enabled build
+          meson compile -C build