fix: auto-detect CMake vs autotools for warnet image build#801

b-l-u-e wants to merge 2 commits intobitcoin-dev-project:mainbitcoin-dev-project/warnet:mainfrom

b-l-u-e:fix/769-warnet-image-build-cmake-autotoolsb-l-u-e/warnet:fix/769-warnet-image-build-cmake-autotoolsCopy head branch name to clipboard