CI: Drop SonarQube and Schutzbot in favor of Snyk (HMS-3696)

Snyk is now being used for code analysis in favor of Sonarqube. This
commit drops Sonarqube. Schutzbot was only neccessary for running
SonarQube, so it has also been dropped.

.github/workflows/trigger-gitlab.yml

@@ -1,33 +0,0 @@
-# inspired by rhinstaller/anaconda
-
-name: Trigger GitLab CI
-
-on:
-  push:
-    branches:
-      - main
-
-jobs:
-  trigger-gitlab:
-    runs-on: ubuntu-latest
-    env:
-      IMAGEBUILDER_BOT_GITLAB_SSH_KEY: ${{ secrets.IMAGEBUILDER_BOT_GITLAB_SSH_KEY }}
-    steps:
-      - name: Install Dependencies
-        run: |
-          sudo apt install -y jq
-
-      - name: Clone repository
-        uses: actions/checkout@v3
-        with:
-          fetch-depth: 0
-
-      - name: Push to gitlab
-        run: |
-          mkdir -p ~/.ssh
-          echo "${IMAGEBUILDER_BOT_GITLAB_SSH_KEY}" > ~/.ssh/id_rsa
-          chmod 400 ~/.ssh/id_rsa
-          touch ~/.ssh/known_hosts
-          ssh-keyscan -t rsa gitlab.com >> ~/.ssh/known_hosts
-          git remote add ci git@gitlab.com:redhat/services/products/image-builder/ci/image-builder-frontend.git
-          git push -f ci