Detect changes in local file registries

### Description of the feature request:

I was adding a module to BCR and testing it out locally with `--resistry file:///home/....` and got an error due to a mismatched sha256. Correcting the error in my local registry and re-running `bazel build` still reported the same error. I had to `bazel clean` in order to refresh the registry.

### Which category does this issue belong to?

External Dependency

### What underlying problem are you trying to solve with this feature?

_No response_

### Which operating system are you running Bazel on?

_No response_

### What is the output of `bazel info release`?

_No response_

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse HEAD` ?

```text

```

### Have you found anything relevant by searching the web?

_No response_

### Any other information, logs, or outputs that you want to share?

_No response_

Reproduce the report with a local `file:///home/...` registry, `bazel build`, and a corrected sha256, then compare the result before and after `bazel clean`. The change is complete when Bazel detects the updated local registry without requiring a clean; the issue does not name source files or tests to start from.

Written by the indexing model from the issue text.