Enable end-of-line normalization in `.gitattributes`
Enable end-of-line normalization in `.gitattributes`

See https://github.com/actions/checkout/issues/135, this fixes a test failure
in GitHub Actions involving the line endings in a test output.

PiperOrigin-RevId: 345821714

cushon/error-prone,google/error-prone,cushon/error-prone,cushon/error-prone,cushon/error-prone,google/error-prone