SLO1 performance issues

[majamassarini]

We are having SLO1 error budget issues.

These are mostly caused by db performance issues and we are working on them:

• Speed-up queries after introduction of groups #1908.

We are also planning further improvements:

• Periodically delete old data from the db #1923
• Load the package config once per pipeline run #1940
• Check if the repo is private only when the pipeline is started #1942
• Don't update test flags while builds are still in progress #1943

[lachmanfrantisek]

Related to the research currently being worked on.

[lbarcziova]

Recently several improvements regarding this were implemented: storing the package configuration in DB, not running private repo check for result events and optimizing getting the PR info via API; so let's see how the situation will improve. If needed, we can implement also #1923 .