refactor(alerts): lower urgent-authorized-projects execution SLO

What

Reduce the urgent-authorized-projects SLO from 0.98 to 0.95

Why

We keep getting paged constanly, 12 pages in the last week and they are un-actionable alerts.

There are some architecture changes in https://gitlab.com/groups/gitlab-org/-/epics/8200 that will fix the problem, but it will take a while.

Before	After
source	source

Reference: https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/24341