[isabelle-dev] Isabelle2023-RC3 release fork today

[Makarius]

The fork of the isabelle-dev vs. isabelle-release repository will happen later 
today, within a few hours. There will be Isabelle2023-RC3 emerging from this.

To avoid confusion on isabelle-dev repository, and resulting re-spin of 
long-running Isabelle/AFP tests, further changes be postponed.

Important changes for Isabelle2023 can still be discussed, to see if it is for 
Isabelle2023-RC3 today, or Isabelle2023-RC4 later on.

Everything else is for post-Isabelle2023 ...


	Makarius