release version 9.0

Problem:    About time to release Vim 9.0.
Solution:   Update the version number everywhere.
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index e24cfbf..84ab1fb 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 8.2.  Last change: 2022 Jun 27
+*options.txt*	For Vim version 9.0.  Last change: 2022 Jun 27
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar