Bump bigdecimal from 3.1.7 to 3.1.8

Bumps [bigdecimal](https://github.com/ruby/bigdecimal) from 3.1.7 to 3.1.8.
- [Release notes](https://github.com/ruby/bigdecimal/releases)
- [Changelog](https://github.com/ruby/bigdecimal/blob/master/CHANGES.md)
- [Commits](ruby/bigdecimal@v3.1.7...v3.1.8)

---
updated-dependencies:
- dependency-name: bigdecimal
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -10,7 +10,7 @@ GEM
  fiber-annotation
  io-event (~> 1.1)
  timers (~> 4.1)
- bigdecimal (3.1.7)
+ bigdecimal (3.1.8)
  colorator (1.1.0)
  concurrent-ruby (1.3.4)
  console (1.27.0)