text: Title: narrow gaps in 2d kernel density diagram
  Body: Hi there!
  
  When I plot a 2d kernel density diagram, there are narrow gaps between  the adjacent contours (not white lines).
  
  I am wondering if there is anyway to fill these gaps, thanks!
  
  ![1](https://github.com/mwaskom/seaborn/assets/2960864/0cd69bb5-0ba4-414a-a886-d71a8452785f)
  