Update roxmltree requirement from 0.17 to 0.18

Updates the requirements on [roxmltree](https://github.com/RazrFalcon/roxmltree) to permit the latest version.
- [Release notes](https://github.com/RazrFalcon/roxmltree/releases)
- [Changelog](https://github.com/RazrFalcon/roxmltree/blob/master/CHANGELOG.md)
- [Commits](RazrFalcon/roxmltree@v0.17.0...v0.18.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

bindings-generator/Cargo.toml

@@ -22,7 +22,7 @@ miniserde = "0.1.16"
 proc-macro2 = "1"
 quote = "1"
 regex = { version = "1.5.5", default-features = false, features = ["std"] } # for security: https://blog.rust-lang.org/2022/03/08/cve-2022-24713.html
-roxmltree = "0.17"
+roxmltree = "0.18"
 syn = { version = "1", features = ["full", "extra-traits", "visit"] }
 unindent = "0.2.0"
 which = { optional = true, version = "4" }