Finalize release 5.9.0

ARM.CMSIS.pdsc

@@ -8,8 +8,7 @@
   <url>http://www.keil.com/pack/</url>
 
   <releases>
-    <release version="5.9.0">
-      Active development ...
+    <release version="5.9.0" date="2022-05-02">
       CMSIS-Core(M): 5.6.0
        - Arm Cortex-M85 cpu support
        - Arm China STAR-MC1 cpu support