Remove Sonarqube

Sonarqube has been failing for some time (seems like a user/credential
problem).

There will be discussion on how we'll resolve this, but that will be
sometime in the future. For now we are just removing the action.

Signed-off-by: Martín Marqués <martin.marques@enterprisedb.com>

.github/workflows/sonarqube-scan.yml

@@ -1,37 +0,0 @@
-name: SonarQube Scan
-on:
-  pull_request:
-  push:
-    branches: [ master ]
-  workflow_dispatch:  
-jobs:
-  sonarQube:
-    name: SonarQube-Job
-    runs-on: ubuntu-latest
-    steps:
-    
-      - name: Checkout source repo
-        uses: actions/checkout@v1
-        with:
-          ref: '${{ github.head_ref }}'
-    
-      - name: Checkout GitHub Action Repo
-        uses: actions/checkout@master
-        with:
-          repository: EnterpriseDB/edb-github-actions.git
-          ref: master
-          token: ${{ secrets.GH_SLONIK }}
-          path: .github/actions/edb-github-actions
-          
-      - name: SonarQube Scan
-        uses: ./.github/actions/edb-github-actions/sonarqube
-        with:
-            REPO_NAME: '${{github.event.repository.name}}'
-            SONAR_PROJECT_KEY: EnterpriseDB_repmgr
-            SONAR_URL: '${{secrets.SONARQUBE_URL}}'
-            SONAR_LOGIN: '${{secrets.SONARQUBE_LOGIN}}'
-            PULL_REQUEST_KEY: '${{github.event.number}}'
-            PULL_REQUEST_BRANCH: '${{github.head_ref}}'
-            PULL_REQUEST_BASE_BRANCH: '${{github.base_ref}}'
-            REPO_DEFAULT_BRANCH: '${{github.event.repository.default_branch}}'
-            REPO_EXCLUDE_FILES: '*properties*,**/src/test/**/*,**/*.sql,**/docs/**/*,**/*/*.java'