[ANN] Pharo 13 Freeze

We are coming close to the Pharo13 release date (TBA).

Thus, we are freezing the branch for new features, and we opened the Pharo14 branch for new developments.

Do not hesitate to still propose bugfixes to the Pharo13 branch.

Today, we also have a Pharo sprint at the Inria lab, we are probably going over the PRs and moving their base to Pharo14 if needed.