CI: automatically skip builds for commits without any changes in the source files

    variables:

        <<: *default_cmake_flags

        BUILD_TYPE: Debug

    only:

        changes:

            - src/**/*.{h,hpp,cpp,cu}

            - Documentation/Tutorials/**/*.{h,hpp,cpp,cu}

            - "**/CMakeLists.txt"

# Dummy build job to ensure that a pipeline is created for a merge request, even

# when there were no changes.

dummy build job:

    stage: build

    script: echo "dummy"

    except:

        changes:

            - src/**/*.{h,hpp,cpp,cu}

            - Documentation/Tutorials/**/*.{h,hpp,cpp,cu}

            - "**/CMakeLists.txt"

# Cuda builds are specified first because they take more time than host-only builds,

# which can be allocated on hosts whitout GPUs.