Have org.apache.logging.log4j.util.Base64Util invoke java.util.Base64…

[jluehe]

… directly instead of reflectively (#3686)

[A clear and concise description of what the pull request is for along with a reference to the associated issue IDs, if they exist.]

Checklist

• Base your changes on 2.x branch if you are targeting Log4j 2; use main otherwise
• ./mvnw verify succeeds (if it fails due to code formatting issues reported by Spotless, simply run ./mvnw spotless:apply and retry)
• Non-trivial changes contain an entry file in the src/changelog/.2.x.x directory
• Tests for the changes are provided
• Commits are signed (optional, but highly recommended)

[ppkarwasz]

Thanks for the contribution — the changes look good to me!

Since this PR doesn’t introduce any new methods, no additional unit tests are needed. However, there are a couple of small tasks to complete before we can proceed with merging:

• Commit Signatures: All commits must be GPG-signed and verified. Please sign your commits in accordance with our branch protection rule. For guidance, refer to GitHub's documentation on commit signature verification.

• Changelog Entry: Please add a changelog entry under src/changelog/.2.x.x. You can find instructions in the Log4j Changelog Entry File Guide.

Let me know if you need any help with these steps!

[github-actions]

Job	Requested goals	Build Tool Version	Build Outcome	Build Scan®
build-macos-latest	clean install	3.9.8	✅
build-ubuntu-latest	clean install	3.9.8	✅
build-windows-latest	clean install	3.9.8	✅

Generated by gradle/develocity-actions

[jluehe]

However, there are a couple of small tasks to complete before we can proceed with merging: ...

Thank you, @ppkarwasz! I've recreated the PR at #3690 with the missing items. Closing this PR