Gazelle does not pick up files added by patch

### What version of rules_go are you using?

0.50.0

### What version of gazelle are you using?

0.38.0

### What version of Bazel are you using?

7.3.1

### Does this issue reproduce with the latest releases of all the above?

Yes

### What operating system and processor architecture are you using?

macOS

### Any other potentially useful information about your toolchain?

### What did you do?

Attepmted to apply [this patch](https://github.com/user-attachments/files/16852819/testcontainers-auth-errors.patch) with the following directive after our `use_repo(go_deps,...` statement in `MODULE.bazel`:
```
go_deps.module_override(
patch_strip = 1,
patches = [
"//:testcontainers-auth-errors.patch",
],
path = "github.com/testcontainers/testcontainers-go",
)
```

### What did you expect to see?

A successful build.

### What did you see instead?

```
external/gazelle~~go_deps~com_github_testcontainers_testcontainers_go/docker_auth.go:128:25: undefined: getRegistryCredentials
```

Gazelle does not seem to pick up the `docker_config.go` file added by the patch; manually adding it to the generated `BUILD.bazel` file solves the problem.

Start with the MODULE.bazel go_deps.module_override example and the generated BUILD.bazel entry for github.com/testcontainers/testcontainers-go. Reproduce the failure on macOS using docker_auth.go, the added docker_config.go, and the supplied patch, then trace how Gazelle processes patched external repositories. Done means a successful build without manually editing the generated BUILD.bazel file.

Written by the indexing model from the issue text.