chore(gradle): Remove duplicate testImplementation dependency

[guicamest]

Pull Request Description

This pull request remove duplicate org.testcontainers:testcontainers:1.18.3 dependency in build.gradle.kts

Acceptance Test

• Building the code with gradle clean build still works.

Questions

• Does this pull request break backward compatibility?

  • Yes and my commit follows the Conventional Commits Specification
  • [X} No

• Does this pull request require other pull requests to be merged first?

  • Yes, please see #...
  • No

• Does this require an update of the documentation?

  • Yes, please see [provide details here]
  • No

[carlspring]

Thank you!

[guicamest]

Thank you!

Thanks for supporting this great library!