Avoid setup-fortran bootstrap failures in intel-ifx CMake CI job

[Copilot]

The intel-ifx-cmake-build (ubuntu-latest, Release, intel, 2025.2) job was failing before execution during Actions setup, not during configure/build/test. The failure came from fortran-lang/setup-fortran@v1 transitively downloading mamba-org/setup-micromamba, which hit GitHub's 429 Too Many Requests limit.

• Scope

  • Restricts the change to intel-ifx-cmake-build
  • Leaves the rest of the workflow unchanged

• What changed

  • Removes fortran-lang/setup-fortran@v1 from the Intel IFX CMake job
  • Adds explicit Intel oneAPI APT repository setup in the job
  • Installs the required versioned Intel compiler packages directly alongside the existing MKL packages
  • Preserves the existing compiler selection by sourcing setvars.sh and continuing to configure CMake with ifx/icx

• Effect

  • Eliminates the failing transitive dependency on setup-micromamba
  • Keeps the job pinned to the intended Intel toolchain versions already defined in the matrix

- name: Add Intel repository
  run: |
    wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
    sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB
    echo "deb https://apt.repos.intel.com/oneapi all main" | sudo tee /etc/apt/sources.list.d/oneAPI.list
    sudo apt-get update

- name: Install Intel oneAPI toolchain
  run: |
    sudo apt-get install -y \
      intel-oneapi-compiler-fortran-${{ matrix.toolchain.version }} \
      intel-oneapi-compiler-dpcpp-cpp-${{ matrix.toolchain.version }} \
      intel-oneapi-mkl-${{ matrix.toolchain.version }} \
      intel-oneapi-mkl-devel-${{ matrix.toolchain.version }}

[thfroitzheim]

Is this still relevant?

[robin-dahl]

@thfroitzheim No, this can be deleted