Add CI config for the deployments blockers report

What does this MR do and why?

Add CI config to generate the deployments blockers report (Example)

This job will run every Monday and generate a report that:

• Includes blockers (release and incident issues) that blocked GitLab.com environments in the previous week.
• Assist release managers in filling out gitlab-com/gl-infra&659 (closed)
  • It replaces the manual compilation done week by week on https://docs.google.com/spreadsheets/d/1wzZE-3EU14jS0tkEDWrW7oCLH5Xr9ptwxQ8DEDgCxTA/edit#gid=363492491

Related to gitlab-com/gl-infra/delivery#2551 (closed)

Also, includes some logging and minor fixes.

Author Check-list

• Has documentation been updated?