ci: fix colon syntax error

Author: paweldomaradzki-dt

.github/workflows/snyk.yaml

@@ -51,7 +51,8 @@ jobs:
         run: snyk test --all-projects --sarif-file-output=result.sarif --severity-threshold=medium
 
       - name: Replace security-severity undefined for license-related findings 
-        run: sed -i 's/"security-severity": "undefined"/"security-severity": "0"/g' snyk.sarif
+        run: |
+          sed -i 's/"security-severity": "undefined"/"security-severity": "0"/g' snyk.sarif
 
       - name: Upload result to GitHub Code Scanning
         uses: github/codeql-action/upload-sarif@v3