Merge pull request OpenMathLib#5395 from martin-frbg/fixloongsonCI

Fix libffi6 download in the Loongarch64_clang CI job (for now)

Author: martin-frbg

.github/workflows/loongarch64_clang.yml

@@ -35,7 +35,7 @@ jobs:
 
       - name: Install libffi6
         run: |
-          wget http://ftp.ca.debian.org/debian/pool/main/libf/libffi/libffi6_3.2.1-9_amd64.deb
+          wget https://download.nvidia.com/cumulus/apt.cumulusnetworks.com/pool/upstream/libf/libffi/libffi6_3.2.1-9_amd64.deb
           sudo dpkg -i libffi6_3.2.1-9_amd64.deb
 
       - name: Install APT deps