Update assert_cmd requirement from 1.0 to 2.0

Updates the requirements on [assert_cmd](https://github.com/assert-rs/assert_cmd) to permit the latest version.
- [Release notes](https://github.com/assert-rs/assert_cmd/releases)
- [Changelog](https://github.com/assert-rs/assert_cmd/blob/master/CHANGELOG.md)
- [Commits](assert-rs/assert_cmd@v1.0.0...v2.0.0)

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

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

mlar/Cargo.toml

@@ -26,6 +26,6 @@ tar = "0.4"
 rand_chacha = "0.2"
 
 [dev-dependencies]
-assert_cmd = "1.0"
+assert_cmd = "2.0"
 assert_fs = "1.0"
 permutate = "0.3"