Further split up Gemfile into groups

This is now possible thanks to sorbet/sorbet#7718.

Homebrew/brew@3b1c171

Dockerfile

@@ -85,7 +85,7 @@ RUN mkdir -p \
   && git -C .linuxbrew/Homebrew remote set-url origin https://github.com/Homebrew/brew \
   && git -C .linuxbrew/Homebrew fetch origin \
   && HOMEBREW_NO_ANALYTICS=1 HOMEBREW_NO_AUTO_UPDATE=1 brew tap --force homebrew/core \
-  && brew install-bundler-gems \
+  && brew install-bundler-gems --groups=all \
   && brew cleanup \
   && { git -C .linuxbrew/Homebrew config --unset gc.auto; true; } \
   && { git -C .linuxbrew/Homebrew config --unset homebrew.devcmdrun; true; } \