Update Scala to 2.13.7

[4e6]

[ci no changelog needed]

Pull Request Description

PR updates the Scala compiler and dependencies.

Here are the effective changes (everything excluding the last commit with the legal stuff) 33f1c4b...df6f004

Changelog:

• update scala to 2.13.7
• update SBT to 1.6.1
• update SBT plugins
• update scala dependencies
• update changed APIs
• fix: SuggestionHandlerSpec test initialization

Important Notes

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the Scala, Java, and Rust style guides.
• All documentation and configuration conforms to the markdown and YAML style guides.
• All code has been tested where possible.

[wdanilo]

I think there should be info in the description of this PR about what's really happening there, because clearly its not only scala bump.

[4e6]

clearly its not only scala bump.

It's Scala compiler and dependencies. There is a lot of legal-review noice in the diff. Here are the effective changes (changes excluding the last commit with the legal stuff) 33f1c4b...df6f004

I'll update the description