Update roxmltree requirement from 0.20 to 0.21

Updates the requirements on [roxmltree](https://github.com/RazrFalcon/roxmltree) to permit the latest version.
- [Changelog](https://github.com/RazrFalcon/roxmltree/blob/master/CHANGELOG.md)
- [Commits](RazrFalcon/roxmltree@v0.20.0...v0.21.1)

---
updated-dependencies:
- dependency-name: roxmltree
  dependency-version: 0.21.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

msixbundle/Cargo.toml

@@ -18,7 +18,7 @@ sdk-discovery = ["dep:winreg"]
 [dependencies]
 anyhow = "1"
 thiserror = "1"
-roxmltree = "0.20"
+roxmltree = "0.21"
 winreg = { version = "0.52", optional = true }
 
 [dev-dependencies]