bug: ignoring next-env.d.ts file causes issues in CI

[FleetAdmiralJakob]

Provide environment information

Here are the specs of my Laptop but they don't help in this case as this is an error in CI because the next-env.d.ts file is not being pushed and lets typechecks fail:

  System:
    OS: macOS 15.1.1
    CPU: (8) x64 Intel(R) Core(TM) i5-8279U CPU @ 2.40GHz
    Memory: 67.98 MB / 8.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.18.0 - ~/.nvm/versions/node/v20.18.0/bin/node
    npm: 10.9.1 - ~/.nvm/versions/node/v20.18.0/bin/npm
    pnpm: 9.15.4 - ~/Library/pnpm/pnpm
    Watchman: 2024.12.02.00 - /usr/local/bin/watchman

Describe the bug

Because next-env.d.ts is not being pushed to the repo it causes issues in CI with the typechecks like these:

https://github.com/orgs/community/discussions/59493

Reproduction repo

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To reproduce

Remove the env.d.ts file from your project and try to typecheck it.

Additional information

No response