fix(deps): update dependency nodebb-theme-slick to v1.4.20 (#10084)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

install/package.json

@@ -94,7 +94,7 @@
         "nodebb-rewards-essentials": "0.2.0",
         "nodebb-theme-lavender": "5.3.1",
         "nodebb-theme-persona": "11.3.10",
-        "nodebb-theme-slick": "1.4.19",
+        "nodebb-theme-slick": "1.4.20",
         "nodebb-theme-vanilla": "12.1.13",
         "nodebb-widget-essentials": "5.0.4",
         "nodemailer": "^6.5.0",