Bump the magik language server to 0.9.0 (#4347)

Release: https://github.com/StevenLooman/magik-tools/releases/tag/0.9.0
Change log: https://github.com/StevenLooman/magik-tools/blob/595e49f66895e5799d9cd8562c6c9cf7582e7429/CHANGES.md?plain=1#L3

CC: @StevenLooman

Author: sebastiaanspeck

clients/lsp-magik.el

@@ -34,7 +34,7 @@
   :tag "Lsp Magik"
   :package-version '(lsp-mode . "8.0.1"))
 
-(defcustom lsp-magik-version "0.8.3"
+(defcustom lsp-magik-version "0.9.0"
   "Version of LSP server."
   :type `string
   :group `lsp-magik