Bump merge from 1.2.0 to 1.2.1 in /benchmark

Bumps [merge](https://github.com/yeikos/js.merge) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/yeikos/js.merge/releases)
- [Commits](swordev/merge@v1.2.0...v1.2.1)

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