fix: dependabot alert is-svg (#4937)

* fix: dependabot alert is-svg

https://youtrack.weseek.co.jp/issue/GW-7619
- Upgrade optimize-css-assets-webpack-plugin to v6.0.1 , is-svg no more required

* Revert "fix: dependabot alert is-svg"

This reverts commit 337fe6f9b0c25fc4f1381177fd83fa57f5014315.

* Rebuild cssnano

- Rebuild cssnano v4.1.10, resolved by v4.1.11.
- No more is-svg required

Co-authored-by: Yuki Takei <yuki@weseek.co.jp>