bookmark+: legacy key syntax in Emacs 30?

[Christopher Howard]

I downloaded the latest files from the wiki but am still getting the same error 
when I require 'bookmark+.

I do not know much about keymaps at this point, but the offending line is in 
bookmark+-key.el:

``` elisp
(define-key ctl-x-map "rK" 'bmkp-set-desktop-bookmark)        ; `C-x r K' (also 
`C-x x K', `C-x x c K')
```

I see in the Emacs 30 documentation at least that define-key is considered now 
a legacy function, and `keymap-set' is recommended instead. Perhaps something 
broke in define-key from 29->30, so that it no longer recognizes correctly the 
legacy string syntax?

I'm CC'ing emacs-devel in hopes that an SME will weigh in on this.

-- 
Christopher Howard