CI: switch QUIC Interop on LibreSSL to common docker image

previously we used different docker images for different SSL libs,
now all of them are merged into one, lets switch to it

Author: chipitsine

.github/workflows/quic-interop-libressl.yml

@@ -30,19 +30,16 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Clone docker image definition
-        run: |
-          git clone -b libressl https://github.com/haproxytech/haproxy-qns
-
       - name: Build and push Docker image
         id: push
         uses: docker/build-push-action@v5
         with:
           context: haproxy-qns
           push: true
+          build-args: |
+            SSLLIB: LibreSSL
           tags: ghcr.io/${{ github.repository }}:libressl
 
-
   run:
     needs: build
     strategy: