Merge pull request #12756 from vector-im/t3chguy/gemini

Remove remainders of gemini-scrollbar and react-gemini-scrollbar

src/vector/index.js

@@ -21,7 +21,6 @@ limitations under the License.
 // Require common CSS here; this will make webpack process it into bundle.css.
 // Our own CSS (which is themed) is imported via separate webpack entry points
 // in webpack.config.js
-require('gemini-scrollbar/gemini-scrollbar.css');
 require('gfm.css/gfm.css');
 require('highlight.js/styles/github.css');