Add C++-Modules Based Linux CI workflow

- This adds a set of CI tests for linux that include compilers that
  support modules
- This CI workflow uses ninja as the build system generator
- Can be integrated with the other linux workflow after successful
  testing

Author: MathewBensonCode

.github/workflows/linux-modules.yml

@@ -0,0 +1,85 @@
+name: linux-modules
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        cxx: [ g++-14, g++-15, clang++-16, clang++-17]
+        build_type: [ Debug, Release ]
+        std: [17, 20]
+        include:
+          - cxx: g++-14
+            install: sudo apt-get install g++-14
+          - cxx: g++-15
+            install: sudo apt-get install g++-15
+          - cxx: clang++-16
+            install: sudo apt-get install clang-16 libc++-16-dev libc++abi-16-dev
+          - cxx: clang++-16
+            cxxflags: -stdlib=libc++
+            install: sudo apt-get install clang-16 libc++-16-dev libc++abi-16-dev
+          - cxx: clang++-17
+            install: sudo apt-get install clang-17 libc++-17-dev libc++abi-17-dev
+          - cxx: clang++-17
+            cxxflags: -stdlib=libc++
+            install: sudo apt-get install clang-17 libc++-17-dev libc++abi-17-dev
+
+    steps:
+    - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
+
+    - name: Set timezone
+      run: sudo timedatectl set-timezone 'Europe/Kyiv'
+
+    - name: Add repositories for newer GCC
+      run: |
+        sudo apt-add-repository ppa:ubuntu-toolchain-r/test
+
+    - name: Add Ubuntu mirrors
+      run: |
+        # GitHub Actions caching proxy is at times unreliable
+        # see https://github.com/actions/runner-images/issues/7048.
+        mirrors=/etc/apt/mirrors.txt
+        printf 'http://azure.archive.ubuntu.com/ubuntu\tpriority:1\n' | \
+          sudo tee $mirrors
+        curl http://mirrors.ubuntu.com/mirrors.txt | sudo tee --append $mirrors
+        sudo sed -i \
+          "s~http://azure.archive.ubuntu.com/ubuntu/~mirror+file:$mirrors~" \
+          /etc/apt/sources.list
+
+    - name: Create build environment
+      run: |
+        sudo apt-get update
+        ${{matrix.install}}
+        sudo apt install locales-all
+        cmake -E make_directory ${{runner.workspace}}/build
+
+    - name: Configure
+      working-directory: ${{runner.workspace}}/build
+      env:
+        CXX: ${{matrix.cxx}}
+        CXXFLAGS: ${{matrix.cxxflags}}
+      run: |
+        cmake -DCMAKE_BUILD_TYPE=${{matrix.build_type}} \
+              -G Ninja \
+              -DCMAKE_CXX_STANDARD=${{matrix.std}} \
+              -DCMAKE_CXX_VISIBILITY_PRESET=hidden \
+              -DCMAKE_VISIBILITY_INLINES_HIDDEN=ON \
+              -DFMT_DOC=OFF -DFMT_PEDANTIC=ON \
+              ${{matrix.fuzz}} -DBUILD_SHARED_LIBS=ON $GITHUB_WORKSPACE
+
+    - name: Build
+      working-directory: ${{runner.workspace}}/build
+      run: |
+        threads=`nproc`
+        cmake --build . --config ${{matrix.build_type}} --parallel $threads
+
+    - name: Test
+      working-directory: ${{runner.workspace}}/build
+      run: ctest -C ${{matrix.build_type}}
+      env:
+        CTEST_OUTPUT_ON_FAILURE: True