Bump dependency_validator from 3.2.3 to 5.0.3 (#430)

Bumps [dependency_validator](https://github.com/Workiva/dependency_validator) from 3.2.3 to 5.0.3.
- [Release notes](https://github.com/Workiva/dependency_validator/releases)
- [Changelog](https://github.com/Workiva/dependency_validator/blob/master/CHANGELOG.md)
- [Commits](Workiva/dependency_validator@3.2.3...5.0.3)

---
updated-dependencies:
- dependency-name: dependency_validator
  dependency-version: 5.0.3
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pubspec.yaml

@@ -17,7 +17,7 @@ dev_dependencies:
   build_test: ^2.1.2
   build_web_compilers: '>=3.2.6 < 5.0.0'
   collection: ^1.15.0
-  dependency_validator: ^3.0.0
+  dependency_validator: ">=3.0.0 <6.0.0"
   json_serializable: ^6.6.1
   lints: ^5.0.0
   nock: ^1.1.3