docs: update changelog for iBotPeaches/Apktool#4021

Author: iBotPeaches

docs/unreleased.mdx

@@ -27,6 +27,7 @@ The changelog of the upcoming release, subject to change prior to finalization.
 - [[#3994](https://github.com/iBotPeaches/Apktool/pull/3994)] Fix support for feature flags prefixed with exclamation mark. (Thanks IgorEisberg)
 - [[#3997](https://github.com/iBotPeaches/Apktool/issues/3997)] Fix building on headless CI systems.
 - [[#3990](https://github.com/iBotPeaches/Apktool/pull/3990)] Upgrade `guava` to `33.5.0-jre`.
+- [[#4021](https://github.com/iBotPeaches/Apktool/pull/4021)] Upgrade `commons-io` to `2.21.0`.
 - [[#3998](https://github.com/iBotPeaches/Apktool/pull/3998)] Upgrade `commons-lang3` to `3.19.0`.
 - [[#4003](https://github.com/iBotPeaches/Apktool/pull/4003)] Upgrade `gradle/actions` to `5.0.0`.
 - [[#4011](https://github.com/iBotPeaches/Apktool/pull/4011)] Upgrade `github/codeql-action` to `v4`.