Another attempt to fix autodoc upload

Description

Problem: autodoc upload now fails in master because it has untracked files in /autodoc and they make it impossible to checkout another branch (where these files are present).

error: The following untracked working tree files would be overwritten by checkout:
	autodoc/AbstractLedger.md
	autodoc/GenericWithCustomErrors.md
	autodoc/ManagedLedger.md
Please move or remove them before you switch branches.
Aborting

Solution: move those files to a temporary directory before checkout, then move them back.

Related issue(s)

None

✅ Checklist for your Merge Request

Related changes (conditional)

• Tests (see short guidelines)

  • If I added new functionality, I added tests covering it.
  • If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.

• Documentation

  • I checked whether I should update the docs and did so if necessary:
    • Root README and other README.md files
    • Haddock
    • docs/
  • I updated changelog files of all affected packages released to Hackage if my changes are externally visible.

Stylistic guide (mandatory)

• My commits comply with the following policy.
• My code complies with the style guide.