fix(codeowners): Fix bug with multiple codeowners

[roggenkemper]

this pr fixes a bug with codeowners where the wrong codeowner was selected. this is because get_issue_owners returns 2 owners so when auto-assignment happened, it only filtered by type. But in the case that there were 2 owners of the same type, it didn't specify which one to pick. Since they are created in the correct order, we can sort by date_created to find the one that's created first which should be the correct one.

fixes https://github.com/getsentry/sentry/issues/73021 Closes https://github.com/getsentry/sentry/issues/73021