Closing figures does not work

还没有人认领这个 Issue。

### How to reproduce
```
%matplotlib widget

import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure(1)
plt.plot(np.sin(np.linspace(0, 20, 100)))
```
and then
```
plt.close(1)
```
### Expected behaviour
Plotting canvas disappears.
### Actual behaviour
Figure becomes non-interactive (tools do not work anymore), but canvas is still visible.

### Versions
sys.version: 3.8.6 (tags/v3.8.6:db45529, Sep 23 2020, 15:52:53) [MSC v.1927 64 bit (AMD64)]
ipympl version: 0.8.7
Jupyter notebook running locally in a VS code (version 1.63.2), jupyter extension v2021.11.1001550889

在本地 VS Code Jupyter notebook 中使用 ipympl 0.8.7 重现该示例，然后跟踪 plt.close(1) 如何影响可见的绘图画布及其交互性。当关闭图形会移除绘图画布，同时重现结果不再留下可见的非交互式图形时，这项工作就完成了。

由索引模型根据 Issue 内容生成。