Bump firrtl from `794e4be` to `276533d` (#140)

Bumps [firrtl](https://github.com/freechipsproject/firrtl) from `794e4be` to `276533d`.
- [Release notes](https://github.com/freechipsproject/firrtl/releases)
- [Commits](https://github.com/freechipsproject/firrtl/compare/794e4be836789e2ca36cc92958f0d99fb5b89b5d...276533dfa5e8281da356c30605f32593278e6167

)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>