Bump braces and gulp in /bundles/org.openhab.ui.basic (#2606)

Bumps [braces](https://github.com/micromatch/braces) to 3.0.3 and
updates ancestor dependency [gulp](https://github.com/gulpjs/gulp).
These dependencies need to be updated together.

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