You can now more easily run the update script to finish out an update
and the documentation is updated to match.

For some reason, I never actually published the draft on this one.
Since 4.121.0 will be out shortly, opted to just skip it.

I think the syntax changed when we moved from yarn to npm.

With the update to node.js v24 in vscode and package.json some files have not been updated and still referenced version 22.x.

npm 12 rejects unknown CLI flags, so the npm install path crashes
with EUNKNOWNCONFIG before installing. The flag has been a no-op
since npm 7; remove it from install.sh and the postinstall guard.

…7917)

One was updated by Dependabot, but not the others.

Installing on the wrong node version dies with "FORCE_NODE_VERSION: unbound
variable" instead of explaining itself. The script runs under set -u and
this is the one place the variable is read bare; the three other reads all
default it.

npm install fails on Windows in postinstall with "mklink: command not
found". mklink is a cmd.exe builtin rather than an executable, so the sh
running this script cannot exec it, and every symlink the install needs is
made this way.

The doubled slashes are the usual MSYS escaping, and are safe here because
this branch only runs when the OS was detected as cygwin or mingw.