Release 8.20.1.0

[smelc]

Changelog

- description: |
    Release 8.20.1.0
# uncomment types applicable to the change:
  type:
  # - feature        # introduces a new feature
  # - breaking       # the API has changed in a breaking way
  # - compatible     # the API has changed but is non-breaking
  # - optimisation   # measurable performance improvements
  # - improvement    # QoL changes e.g. refactoring
  # - bugfix         # fixes a defect
  # - test           # fixes/modifies tests
  # - maintenance    # not directly related to the code
  - release        # related to a new release preparation
  # - documentation  # change in code docs, haddocks...

Context

We want to provide #561 to Q&A

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• Self-reviewed the diff

[smelc]

Putting draft, as we want to wait for #599 to be included in this release.