Add FEX-RootFS definition

Add a new definition for a RootFS to be used by FEX (https://src.fedoraproject.org/rpms/fex-emu). This is based on the upstream manifest (https://github.com/FEX-Emu/RootFS/blob/main/Configs/Fedora_40.json).

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

Fedora.kiwi

@@ -47,6 +47,7 @@
 	<include from="this://./teams/sway.xml"/>
 	<include from="this://./teams/budgie.xml"/>
 	<include from="this://./teams/miraclewm.xml"/>
+	<include from="this://./teams/asahi.xml"/>
 	<packages type="bootstrap">
 		<package name="basesystem"/>
 		<package name="filesystem"/>