[CI] Get rid of includes in matrix (in gpu workflow)

It enforces adding extra Windows job, and the BMG runner on Windows
is not enabled yet. Replace it with params set via env vars.

Author: lukaszstolarczuk

.github/workflows/reusable_gpu.yml

@@ -49,16 +49,24 @@ jobs:
         shared_library: ${{ fromJSON(inputs.shared_lib)}}
         os: ${{ fromJSON(inputs.os)}}
         build_type: ${{ fromJSON(inputs.build_type)}}
-        include:
-          - os: 'Ubuntu'
-            compiler: {c: gcc, cxx: g++}
-            number_of_processors: '$(nproc)'
-          - os: 'Windows'
-            compiler: {c: cl, cxx: cl}
-            number_of_processors: '$Env:NUMBER_OF_PROCESSORS'
 
     runs-on: ["DSS-${{inputs.runner}}", "DSS-${{matrix.os}}"]
     steps:
+      # Set number of processes and compiler based on OS
+      - name: "[Win] Establish build params"
+        if : ${{ matrix.os == 'Windows' }}
+        run: |
+          echo "C_COMPILER=cl" >> $GITHUB_ENV
+          echo "CXX_COMPILER=cl" >> $GITHUB_ENV
+          echo "PROCS=$Env:NUMBER_OF_PROCESSORS" >> $GITHUB_ENV
+
+      - name: "[Lin] Establish build params"
+        if : ${{ matrix.os == 'Ubuntu' }}
+        run: |
+          echo "C_COMPILER=gcc" >> $GITHUB_ENV
+          echo "CXX_COMPILER=g++" >> $GITHUB_ENV
+          echo "PROCS=$(nproc)" >> $GITHUB_ENV
+
       - name: Checkout
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
         with:
@@ -89,8 +97,8 @@ jobs:
           -B ${{env.BUILD_DIR}}
           -DCMAKE_INSTALL_PREFIX="${{env.INSTL_DIR}}"
           -DCMAKE_BUILD_TYPE=${{matrix.build_type}}
-          -DCMAKE_C_COMPILER=${{matrix.compiler.c}}
-          -DCMAKE_CXX_COMPILER=${{matrix.compiler.cxx}}
+          -DCMAKE_C_COMPILER=${{env.C_COMPILER}}
+          -DCMAKE_CXX_COMPILER=${{env.CXX_COMPILER}}
           -DUMF_BUILD_SHARED_LIBRARY=${{matrix.shared_library}}
           -DUMF_BUILD_BENCHMARKS=ON
           -DUMF_BUILD_BENCHMARKS_MT=ON
@@ -107,7 +115,7 @@ jobs:
           ${{ matrix.os == 'Windows' && '-DCMAKE_SUPPRESS_REGENERATION=ON' || '' }}
 
       - name: Build UMF
-        run: cmake --build ${{env.BUILD_DIR}} --config ${{matrix.build_type}} -j ${{matrix.number_of_processors}}
+        run: cmake --build ${{env.BUILD_DIR}} --config ${{matrix.build_type}} -j ${{env.PROCS}}
 
       - name: Run tests
         working-directory: ${{env.BUILD_DIR}}