cli: use new eslint plugin + fix issues

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

scripts/check-docs-quality.js

@@ -56,7 +56,7 @@ async function listFiles(dir = '') {
 // caused by the script. In CI, we want to ensure vale linter is run.
 async function exitIfMissingVale() {
   try {
-    // eslint-disable-next-line import/no-extraneous-dependencies
+    // eslint-disable-next-line @backstage/no-undeclared-imports
     await require('command-exists')('vale');
   } catch (e) {
     if (process.env.CI) {