Add dh-python and python3-all to CI build dependencies

Required for Python-based packages:
- secubox-core
- secubox-repo
- secubox-hardening

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/build-packages.yml

@@ -76,7 +76,8 @@ jobs:
           sudo apt-get update -qq
           sudo apt-get install -y -qq \
             build-essential dpkg-dev debhelper devscripts fakeroot \
-            qemu-user-static binfmt-support
+            qemu-user-static binfmt-support \
+            dh-python python3-all python3-setuptools
           if [[ "${{ matrix.arch }}" == "arm64" ]]; then
             sudo apt-get install -y -qq crossbuild-essential-arm64
           fi