build(deps): update rake-compiler-dock requirement in /precompiled

Updates the requirements on [rake-compiler-dock](https://github.com/rake-compiler/rake-compiler-dock) to permit the latest version.
- [Release notes](https://github.com/rake-compiler/rake-compiler-dock/releases)
- [Changelog](https://github.com/rake-compiler/rake-compiler-dock/blob/main/History.md)
- [Commits](rake-compiler/rake-compiler-dock@v1.8.0...v1.9.1)

---
updated-dependencies:
- dependency-name: rake-compiler-dock
  dependency-type: direct:production
...

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

Author: dependabot[bot]

precompiled/Gemfile

@@ -8,6 +8,6 @@ gemspec
 gem "rake", "~> 13.0"
 
 gem "rake-compiler"
-gem "rake-compiler-dock", "1.8.0"
+gem "rake-compiler-dock", "1.9.1"
 
 gem "minitest", "~> 5.0"