Merge from origin/emacs-29

3204825f560 Fix mangled Subject header field when forwarding (Bug#67360)
7591acfe38e Update to Org 9.6.15
240b4594f11 ; * etc/TODO: Add an item about 'Info-hide-note-references'.
01be4fe39d7 * doc/emacs/custom.texi (Modifier Keys): Fix markup (bug#...
55555a6a0d1 org-protocol: Minor copy-edits to Commentary
4696869d3d5 Improve syntax highlighting for python-ts-mode

diff --cc doc/emacs/custom.texi
Simple merge

diff --cc doc/misc/org.org
Simple merge

diff --cc etc/TODO
Simple merge

diff --cc lisp/org/org-entities.el
Simple merge

diff --cc lisp/org/org-macs.el
Simple merge

diff --cc lisp/org/org-protocol.el
Simple merge

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

diff --cc lisp/org/ox-md.el
Simple merge

diff --cc lisp/progmodes/python.el
Simple merge

diff --cc test/lisp/progmodes/python-tests.el
Simple merge