QA issue should be created by QA jobs

QA issue is created by gstg tracking jobs on the deployer pipeline. Technical details about how it's created

1. gstg-track-running is executed before the fleet to track a running environment on staging - Example
   • This job triggers a pipeline on release-tools that executes release:track_deployment with DEPLOY_STATUS as running. Example
     • Records a gstg running deployment for GitLab, Omnibus, Gitaly
     • Creates a new gstg deployment in GitLab, Omnibus and Gitaly Security
     • Adds "workflow::staging"
2. gstg-track is executed after the fleet has been updated. Example
   • This job triggers a pipeline on release-tools that executes release:track_deployment with DEPLOY_STATUS as success. Example
     • Records a successful gstg deployment for GitLab, Omnibus and Gitaly
     • Creates a Sentry deploy
     • Creates QA issue
   • If the deployment failed gstg-track-failure will be executed instead

Proposal

Let the QA jobs triggered in staging handle the creation of the QA issue. Creating the QA issue URL shouldn't be the responsibility of the tracking jobs (it was probably set up this way to send the issue URL to the QA jobs in the deployer). After QA is moved to release-tools #1490 (closed) and probably during #1394, we can move the creation of the QA issue to the QA jobs.