Add build_enabled input (build job optional, off by default)

    # project found in the repository root.

    solution_path:

      default: ""

    # Set to "true" to enable the build job. Off by default: enable it on

    # demand when build output is actually needed.

    build_enabled:

      default: false

    # Set to "true" to enable the test job.

    tests_enabled:

      default: false

  DOTNET_VERSION: "$[[ inputs.dotnet_version ]]"

  BUILD_CONFIGURATION: "$[[ inputs.configuration ]]"

  BUILD_SOLUTION: "$[[ inputs.solution_path ]]"

  BUILD_ENABLED: "$[[ inputs.build_enabled ]]"

  RUN_TESTS: "$[[ inputs.tests_enabled ]]"

  ENABLE_PUBLISH: "$[[ inputs.publish_enabled ]]"

  PUBLISH_OUTPUT: "$[[ inputs.publish_output ]]"

    - if [ -z "$DOTNET_BUILD_ARGS" ]; then echo "No solution/project specified, skipping build." && exit 0; fi

    - dotnet build "$DOTNET_BUILD_ARGS" -p:Configuration="$BUILD_CONFIGURATION"

  artifacts:

    paths:

      - "**/bin/$BUILD_CONFIGURATION/**"

    paths: $[[ inputs.build_artifact_paths ]]

    exclude:

      - "**/obj/**"

    expire_in: 7 days

  rules:

    - if: '$BUILD_ENABLED != "true"'

      when: never

    - if: $CI_PIPELINE_SOURCE == "merge_request_event"

    - if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS

      when: never