Bump CLI version from v2.20.3 to v2.20.4 for integration tests

Author: github-actions[bot]

extensions/ql-vscode/supported_cli_versions.json

@@ -1,5 +1,5 @@
 [
-  "v2.20.3",
+  "v2.20.4",
   "v2.19.4",
   "v2.18.4",
   "nightly"