Fix alpine CI

Author: Ergus

.github/workflows/cmake.yml

@@ -63,11 +63,11 @@ jobs:
         run: g++ --version
 
       - name: Configure CMake
-        run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=Debug
+        run: cmake -B build -DCMAKE_BUILD_TYPE=Debug
 
       - name: Build
-        run: cmake --build ${{github.workspace}}/build
+        run: cmake --build build
 
       - name: Test
-        working-directory: ${{github.workspace}}/build
+        working-directory: build
         run: ctest --output-on-failure