(bugfix): Explicitly load subr-x library (#429)

Ensure the `if-let*` macro definitions is available during compile-time

org-roam-buffer.el

@@ -30,6 +30,7 @@
 ;; This library provides the org-roam-buffer functionality for org-roam
 ;;; Code:
 ;;;; Library Requires
+(eval-when-compile (require 'subr-x))
 (require 'cl-lib)
 (require 'dash)
 (require 's)