Use `releaseRepository` in release action

[hbmartin]

This was replaced in the vanniktech plugin as of 0.28.0 https://vanniktech.github.io/gradle-maven-publish-plugin/changelog/#0280-2024-03-12

Fixes the apparent release action failures e.g. https://github.com/touchlab/KMMBridge/actions/runs/10689342756/job/29631221033