fix(tools): remove duplicate CSS picklist entries (highlightjs#3926)

Author: dschach

CHANGES.md

@@ -18,6 +18,7 @@ New Grammars:
 Developer Tool:
 
 - enh(tools): order CSS options picklist [David Schach][]
+- enh(tools): remove duplicate CSS options [David Schach][]
 
 [Lê Duy Quang]: https://github.com/leduyquang753
 [Mohamed Ali]: https://github.com/MohamedAli00949

tools/developer.html

@@ -272,11 +272,8 @@ <h3>Code</h3>
           <option>github-gist.css</option>
           <option>github.css</option>
           <option>gml.css</option>
-          <option>gml.css</option>
-          <option>googlecode.css</option>
           <option>googlecode.css</option>
           <option>gradient-dark.css</option>
-          <option>gradient-dark.css</option>
           <option>gradient-light.css</option>
           <option>grayscale.css</option>
           <option>hybrid.css</option>
@@ -303,7 +300,6 @@ <h3>Code</h3>
           <option>paraiso-dark.css</option>
           <option>paraiso-light.css</option>
           <option>pojoaque.css</option>
-          <option>pojoaque.jpg</option>
           <option>purebasic.css</option>
           <option>qtcreator-dark.css</option>
           <option>qtcreator-light.css</option>