fix: use gradle 'group' property instead of 'groupId'

[ndr-brt]

What this PR changes/adds

As documented in
https://docs.gradle.org/current/dsl/org.gradle.api.Project.html#org.gradle.api.Project:group

Why it does that

Briefly state why the change was necessary.

Further notes

List other areas of code that have changed but are not necessarily linked to the main feature. This could be method signature changes, package declarations, bugs that were encountered and were fixed inline, etc.

Linked Issue(s)

Closes # <-- insert Issue number if one exists

Checklist

• added appropriate tests?
• performed checkstyle check locally?
• added/updated copyright headers?
• documented public classes/methods?
• added/updated relevant documentation?
• assigned appropriate label? (exclude from changelog with label no-changelog)
• formatted title correctly? (take a look at the CONTRIBUTING and Etiquette for pull requests for details)

[github-actions]

Test Results

38 tests  ±0   38 ✔️ ±0   33s ⏱️ +7s
12 suites ±0     0 💤 ±0 
12 files   ±0     0 ❌ ±0 

Results for commit 6483f06. ± Comparison against base commit 2295e8a.