Release schedule for pyMOR 2024.1

[sdrave]

Hi @pymor/all,

in the previous community meeting, we set the release date to July 5. This means that:

• the soft freeze will be on May 31 (no new feature pull requests entering the release milestone*) and
• the hard freeze will be on June 28 (no new pull requests entering the release*).

Release manager: @sdrave

*with possible exceptions. See the release process checklist for details.