fix: use correct(!) dep to identify latest version

[hartmut-co-uk]

❓ Type of change

• 📖 Documentation (updates to the documentation, readme or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description, Motivation and Context

The dependency io.micronaut:micronaut-core or io.micronaut:micronaut-core-bom does not reflect the correct latest micronaut version but advances upfront. This causes build failures due to transitive dependencies not found.

io.micronaut.platform:micronaut-platform seems to be the correct choice to pin the micronaut version to be used.

🧪 How Has This Been Tested?

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.