chore(deps): update rstest requirement from 0.18 to 0.19

Updates the requirements on [rstest](https://github.com/la10736/rstest) to permit the latest version.
- [Release notes](https://github.com/la10736/rstest/releases)
- [Changelog](https://github.com/la10736/rstest/blob/master/CHANGELOG.md)
- [Commits](la10736/rstest@v0.18.0...v0.19.0)

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

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

libindy_vdr/Cargo.toml

@@ -63,7 +63,7 @@ zmq = "0.9"
 sled = "0.34.7"
 
 [dev-dependencies]
-rstest = "0.18"
+rstest = "0.19"
 time = "0.3"
 indy-data-types = { version = "0.7", default-features = false, features = [
     "rich_schema",