[KEYCLOAK-19130] Remove snyk workflow from the Keycloak repository

.github/workflows/snyk.yml

@@ -1,18 +0,0 @@
-name: Snyk
-on: push
-jobs:
-  security:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@master
-      - name: Run Snyk to check for vulnerabilities
-        uses: snyk/actions/maven-3-jdk-11@master
-        continue-on-error: true # To make sure that SARIF upload gets called
-        env:
-          SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}
-        with:
-          args: --sarif-file-output=snyk.sarif
-      - name: Upload result to GitHub Code Scanning
-        uses: github/codeql-action/upload-sarif@v1
-        with:
-          sarif_file: snyk.sarif