Update mock requirement from ^4.0.3 to >=4.0.3,<6.0.0

Updates the requirements on [mock](https://github.com/testing-cabal/mock) to permit the latest version.
- [Changelog](https://github.com/testing-cabal/mock/blob/master/CHANGELOG.rst)
- [Commits](testing-cabal/mock@4.0.3...5.2.0)

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

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

Author: dependabot[bot]

pyproject.toml

@@ -22,7 +22,7 @@ base58 = "^2.0.1"
 base91 = "^1.0.1"
 pybase62 = ">=0.4.3,<0.6.0"
 click = ">=7.1.2,<9.0.0"
-mock = "^4.0.3"
+mock = ">=4.0.3,<6.0.0"
 pywhat = "3.0.0"
 xortool-ciphey = "^0.1.16"