Remove redundant log

Author: OlegWock

src/webviews/webview-side/vega-renderer/VegaRenderer.tsx

@@ -33,7 +33,6 @@ function useThemeColors(): ThemeColors {
 
     useEffect(() => {
         const observer = new MutationObserver(() => {
-            console.log('Observed body change');
             setThemeColors(getThemeColors());
         });