v6.0.0 Alpha6

[Rot127]

Your checklist for this pull request

• I've documented or updated the documentation of every API function and struct this PR changes.
• I've added tests that prove my fix is effective or that my feature works (if possible)

Detailed description

New release to incorporate the CVE fixes

TODO:

• Add missing apt-get update before installing dependencies. #2832
• Return for failing range asserts to enforce the assumptions. #2829
• Changelog
• Add Alpha imm change to changelog
• rebase

Test plan

...

Closing issues

...