fix debian:buster fix

Author: jhheider

.github/workflows/cd.yml

@@ -91,8 +91,10 @@ jobs:
 
       # debian:buster is archived, so we need to fix its sources.list
       - name: fix debian:buster
-        if: ${{ matrix.platform.container == 'debian:buster-slim' }}
-        run: sed -i 's/deb.debian.org/archive.debian.org/g' /etc/apt/sources.list
+        run: |
+          if test -f /etc/debian_version && grep -q '^10\.' /etc/debian_version; then
+            sed -i 's/deb.debian.org/archive.debian.org/g' /etc/apt/sources.list
+          fi
 
       - run: |
           apt-get update