Rust Dependency: Bump rustversion from 1.0.20 to 1.0.21 (#1151)

Bumps [rustversion](https://github.com/dtolnay/rustversion) from 1.0.20
to 1.0.21.

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Aaron <aaronpop@microsoft.com>

Author: dependabot[bot]

Cargo.lock

@@ -21,7 +21,7 @@ num-traits = { version = "0.2", default-features = false}
 num-derive = { version = "0.4", default-features = false}
 r-efi = "5.2.0"
 scroll = { version = "0.11", default-features = false, features = ["derive"]}
-rustversion = "1.0.20"
+rustversion = "1.0.21"
 spin = "0.5.2"
 
 # By default, the dev profile is used. The default build settings for the dev profile are documented here: