Fixed syntax within Selenium versions matrix

Author: emanlove

.github/workflows/CI.yml

@@ -11,7 +11,7 @@ jobs:
       matrix:
         python-version: [3.8, 3.13.0]  # pypy-3.9
         rf-version: [6.1.1, 7.1.1]
-        selenium-version: [4.24.0, 4.25.0 4.26.1]
+        selenium-version: [4.24.0, 4.25.0, 4.26.1]
         browser: [firefox, chrome, headlesschrome]  #edge
 
     steps: