Modify Generate Your Projects (GYP) files .gyp & .gypi handling in Emacs 30.1

gyp-syntax-mods.el

(defun e/modify-gyp-syntax ()
  "Generate Your Projects (GYP) files .gyp & .gypi files look like JSON,
but can have # comments and single quotes are permitted as string
delimiters. It also permits trailing commas at the end of list and
dictionary content."
  (when (and (stringp buffer-file-name)
	     (string-match "\\.gypi?\\'" buffer-file-name))
    (let ((gyp-syntax-table (copy-syntax-table js-mode-syntax-table)))
      (modify-syntax-entry ?# "<" gyp-syntax-table)
      (modify-syntax-entry ?\n ">" gyp-syntax-table)
      (modify-syntax-entry ?\' "\"" gyp-syntax-table)
      (set-syntax-table gyp-syntax-table))))

(add-to-list 'auto-mode-alist '("\\.gypi?\\'" . js-json-mode))

(add-hook 'js-json-mode-hook (lambda ()
			       (e/modify-gyp-syntax)
			       (editorconfig-apply)))

Also applies EditorConfig rules manually since the built-in editorconfig-mode and js-json-mode don't seem to like each other.