Bump js-base64 from 2.6.2 to 2.6.4 (#14650)

Bumps [js-base64](https://github.com/dankogai/js-base64) from 2.6.2 to 2.6.4.
- [Release notes](https://github.com/dankogai/js-base64/releases)
- [Commits](https://github.com/dankogai/js-base64/compare/2.6.2...2.6.4

)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>