[Bug?]: `yarn init` should not create a new git repo when already inside a git repo

[Yvem]

Self-service

• I'd be willing to implement a fix

Describe the bug

yarn init -2 created a git repo inside my git repo :-/

To reproduce

Steps:

• I created a fresh git repo on GitHub
• I clone it on my machine, enabled corepack
• I created a subfolder and invoked yarn init -2 inside it (100% sure yarn v4 was invoked, I got clear messages about version 4.x.y)
  -🪲 yarn created a git repo inside my git repo

Environment

System:
    OS: macOS 15.5
    CPU: (8) arm64 Apple M2
  Binaries:
    Node: 24.4.0 - /private/var/folders/dv/_cxsbt9x6xj5695nk5qgz1f00000gp/T/xfs-1d9c87b5/node
    Yarn: 4.9.2 - /private/var/folders/dv/_cxsbt9x6xj5695nk5qgz1f00000gp/T/xfs-1d9c87b5/yarn
    npm: 11.4.2 - ~/.nvm/versions/node/v24.4.0/bin/npm

Additional context

A quick check of not being already in a git repo should be performed. Aside my example above, creating a new package/workspace in a monorepo would face the same issue.