Fix byte-compilation warning in project.el

* lisp/emacs-lisp/seq.el (seq-every-p): Autoload it.  This fixes
byte-compilation warning in project.el.

lisp/emacs-lisp/seq.el

@@ -348,6 +348,7 @@ If SEQUENCE is empty, return INITIAL-VALUE and FUNCTION is not called."
         (setq acc (funcall function acc elt)))
       acc)))
 
+;;;###autoload
 (cl-defgeneric seq-every-p (pred sequence)
   "Return non-nil if (PRED element) is non-nil for all elements of SEQUENCE."
   (catch 'seq--break