Merge from origin/emacs-28

b201823f63 Describe problems with invoking Python on MS-Windows
880f2734c9 A better fix for bug#54800
5ee959aa87 Add a comment about cl-concatenate
ab2b822b9b Revert "Make cl-concatenate an alias of seq-concatenate"

diff --cc etc/PROBLEMS
Simple merge

diff --cc lisp/calc/calc.el
Simple merge