ci: add native ARM (Linux + Windows) and Intel macOS runners (#345)

* ci: add native ARM Linux and Intel macOS runners

Add ubuntu-24.04-arm and macos-15-intel to the test-unix matrix to
exercise openlibm natively on both architectures. ARM and aarch64
were previously only tested via QEMU cross-compilation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* ci: add windows-11-arm runner with clangarm64

Adds a Windows ARM64 entry to the Windows matrix using MSYS2's
clangarm64 environment on the windows-11-arm GitHub-hosted runner.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* ci: remove legacy code-coverage-old job

The new code-coverage job (added in #327) runs the external
JuliaMath/openlibm-test suite and uploads to Codecov, superseding
the in-tree `make coverage` job whose Codecov upload was already
disabled.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ViralBShah

.github/workflows/ci.yml

@@ -15,21 +15,24 @@ jobs:
       matrix:
         os:
           - ubuntu-latest
+          - ubuntu-24.04-arm
           - macos-latest
+          - macos-15-intel
     steps:
       - uses: actions/checkout@v6
       - run: make
       - run: make test
   windows:
-    runs-on: windows-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         include:
-          - { sys: mingw64, env: x86_64 }
-          - { sys: mingw32, env: i686 }
-          - { sys: ucrt64,  env: ucrt-x86_64 }  # Experimental!
-          - { sys: clang64, env: clang-x86_64 } # Experimental!
+          - { os: windows-latest,  sys: mingw64,     env: x86_64 }
+          - { os: windows-latest,  sys: mingw32,     env: i686 }
+          - { os: windows-latest,  sys: ucrt64,      env: ucrt-x86_64 }  # Experimental!
+          - { os: windows-latest,  sys: clang64,     env: clang-x86_64 } # Experimental!
+          - { os: windows-11-arm,  sys: clangarm64,  env: clang-aarch64 } # Experimental!
     defaults:
       run:
         shell: msys2 {0}
@@ -42,23 +45,6 @@ jobs:
           install: base-devel mingw-w64-${{matrix.env}}-toolchain
       - run: make
       - run: make test
-  code-coverage-old:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v6
-      - name: Setup LCOV
-        uses: hrishikesh-kadam/setup-lcov@v1
-      - name: Build and Run tests
-        run: make coverage -j
-      # - name: Upload coverage to Codecov
-      #   uses: codecov/codecov-action@v6
-      #   with:
-      #     files: ./cov-html/libopenlibm.info
-      #     token: ${{ secrets.CODECOV_TOKEN }}
-      - uses: actions/upload-artifact@v7
-        with:
-          name: code-coverage-report-old
-          path: ./cov-html/
   code-coverage:
     runs-on: ubuntu-latest
     steps: