Add cmake package

Author: nicodr97

.github/workflows/build.yml

@@ -34,6 +34,7 @@ jobs:
         uses: jirutka/setup-alpine@v1
         with:
           arch: x86
+          packages: cmake
           shell-name: alpine-x86.sh
       - name: Build trimal for Linux x86
         if: matrix.arch == 'x86' && matrix.cpu_instr == 'auto-selected'