Update CI to publish from spdx-spec "develop" and spdx-3-model "develop" branches

[bact]

To support new branch structure and publication of draft specs under development, and also new spec-parser:

• spdx-spec "develop" + spdx-3-model "develop" --> https://spdx.github.com/spdx-spec/v3.1-dev/
  • (this PR)
• spdx-spec "main" + spdx-3-model "main" --> https://spdx.github.com/spdx-spec/v3.0.1/
  • (another PR will be created for this, targetting spdx-spec "main" branch)
• spdx-spec "support/3.0" + spdx-3-model "support/3.0" --> https://spdx.github.com/spdx-spec/v3.0.2-dev/
  • (another PR will be created for this, targetting spdx-spec "support/3.0" branch)
• See full discussion at Publication source branches/tags and target URLs mapping/aliases #1155

[bact]

Turn to draft for now, as we will incorporate a new spec-parser soon.