[Bug] line-chart's top/bottom line's width thinner than others

[appleqzw]

Version

4.9.0

Link to Minimal Reproduction

https://codepen.io/appleqzw-the-encoder/pen/ExdzEQv

Steps to Reproduce

view the site https://codepen.io/appleqzw-the-encoder/pen/ExdzEQv

Current Behavior

In this demo,l set xAxis.show:false and yAxis.show:false,then l set grid.top:0 and grid.bottom:0,I found that the width of the top line is thinner than the others, and the bottom line is the same

if setgrid.top:4 and grid.bottom:4,then the line width is right,is this a bug?

Expected Behavior

Is there any other way to solve this problem?

Environment

- OS:
- Browser:
- Framework:

Any additional comments?

No response

[echarts-bot]

I'm sorry to close this issue for it lacks the necessary title. Please provide a descriptive and as concise as possible title to describe your problems or requests and then the maintainers or I will reopen this issue.

Every good bug report or feature request starts with a title. Your issue title is a critical element as it's the first thing maintainers see.

A good issue title makes it easier for maintainers to understand what the issue is, easily locate it, and know what steps they'll need to take to fix it.

Moreover, it's better to include keywords, as this makes it easier to find the issue self and similar issues in searches.

[plainheart]

The line width is not correctly involved in the calculation of the grid component. It may be enhanced in the future. And #18022 may be related to this issue.