chore: rename groupId and bump version of the maven plugin.

[vpa1977]

• rename the groupId to io.github.rockcrafters to match the repository location

• bump version number to 0.2.1 to match gradle plugin

• [x] Have you signed the CLA?

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[vpa1977]

Bypass merge requirements: trivial change that is checked by CI. Release pipeline ran due to the accidental tag push, disabled in settings now.