Root files not checked out when using sparse checkout

[C302]

When using sparse checkout together with cone mode = true, this completely contradicts documentation.

my personal 2cents: It's a pity to see that such an elementary GH-actions building block contains that amount of issues and receives little amount of GH support.

[cshein45]

I’ve been tracking this behavior as well. When sparse-checkout is initialized with cone mode, the expectation—per Git documentation—is that files in the root directory should be included by default. However, it appears the current action implementation might be overly restrictive with the patterns it generates, effectively "locking out" root-level files unless specifically patterned.
To help the maintainers pinpoint this, could you clarify:

1. Which version of the actions/checkout are you using?
2. Are you seeing this on a specific runner OS (e.g., Ubuntu vs. Windows)?
   As someone actively building on the Movement Network, I rely on these elementary building blocks for high-throughput CI/CD pipelines. Ensuring the integrity of sparse-checkout is vital for monorepo efficiency and developer experience.