build(deps): bump tree-kill from 1.2.1 to 1.2.2 in /examples/lb3-express (#21)

Bumps [tree-kill](https://github.com/pkrumins/node-tree-kill) from 1.2.1 to 1.2.2.
- [Release notes](https://github.com/pkrumins/node-tree-kill/releases)
- [Commits](pkrumins/node-tree-kill@v1.2.1...v1.2.2)

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

Author: dependabot[bot]