Docker image size is blowing up

When comparing the last few releases in
https://console.cloud.google.com/gcr/images/kaggle-images/GLOBAL/python
it is quite noticeable that recently there has been a sudden increase in the docker image size, e.g. from virtual size 6.2 GB of `v125` to virtual size of 8.3 GB of `v129`, i.e. a 34% increase.

When uncompressed, docker reports that `v125` results in a 19 GB container, while `v129` results in a 23 GB container, i.e. a 21% increase.

I noticed this while running (the heaviest of) my workflows on GitHub Actions, randomly getting errors like
```
System.IO.IOException: No space left on device : '/home/runner/runners/2.302.1/_diag/Worker_20230304-204952-utc.log'
```
While surely the amount of disk space that GitHub offers is not your responsibility, you may still want to check if there is any way to keep the size of the docker image under control, and if possible keep it from growing at this rate any further.

まず、リンクされた Google Container Registry イメージを使用して、v125 と v129 の Docker イメージレイヤーとビルド履歴を比較します。どのリリース変更が増加の原因になっているかを特定し、その後のイメージで、既存のイメージ内容を維持しながら、報告された割合では増加しなくなっていることを確認します。

索引モデルが issue の本文から書いたものです。