I do have a plot and want to close the gaps between row group elements as indicated above:

I don't want to change the figsize since it hampers readability. Just need to adjust that white space to my liking. Fiddled with linewidth but no luck. Creating plots with this line:
ax = sns.barplot( y='config', x='value', hue='variable', 
         data=pd.melt(df2, ['config']), orient='h', linewidth=0)