chore: bump version to v0.2.1

Author: YanLien

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "axvm"
 authors = ["aarkegz <aarkegz@gmail.com>"]
-version = "0.2.0"
+version = "0.2.1"
 edition = "2024"
 categories = ["virtualization", "no-std"]
 description = "Virtual Machine resource management crate for ArceOS's hypervisor variant."