eglot-server-programs: Account for new js-json-mode

eglot-server-programs: Account for new js-json-mode

js-json-mode derives from js-mode, so this reordering is necessary to
prevent js-mode's eglot server from starting if a user has something
like this in their config:

    (add-to-hook 'js-json-mode #'eglot-ensure)
    (add-to-hook 'js-mode #'eglot-ensure)

* lisp/progmodes/eglot.el (eglot-server-programs): Move the
json-language-server info before the entry for js-mode, and add on
js-json-mode.  (Bug#58769)