EESSI bot v0.8.0

This is a minor release of the EESSI build-and-deploy bot.

Bug fixes:

• use Ubuntu 24.04 in CI (#316)
• delete pre-existing signature files (#309)

Improvements:

• adding argument --contain when launching the build container (#307)
• use the bot instance's name as namespaces value in a signature (#308)
• determine test coverage (#311)
• support different levels for when a bot instance creates comments on GitHub (#315)

Changes to app.cfg settings (see README.md and app.cfg.example for details):

• NEW (optional) chatlevel in section [bot_control]