Windows: failed to delete output files before executing action (.dll)

### Description of the problem / feature request:

When compiling on Windows, sometimes .dll cannot be deleted.
The typical error message is: " xx.dll: failed to delete output files before executing action"

I am using remote_cache with remote_download_minimal, and it seems those items that actually are left in the local cache, sometimes cannot be deleted.

Manually you can delete the .dlls just fine, so a workaround for now is to search the local cache for .dlls and delete them before server side compilation.

I have previously seen problems when defender or anti-virus is temporarily locking files. However this failure is permanent: Bazel cannot delete the files, the user can.

### Feature requests: what underlying problem are you trying to solve with this feature?

1. Get a better error message when this error occurs (permission, read error etc).
2. Create a more stable way to delete files on windows (retry?, unlocking?)

### Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

It is sporadic, but probably connected to remote_cache

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

Windows 10

### What's the output of `bazel info release`?

1.2.0

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

Nothing

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

No.

The issue names no source file or test. Start by investigating the Windows 10 build path involving remote_cache and remote_download_minimal, using the sporadic .dll deletion failure as the reproduction target. Done means the failure can be reproduced or characterized and the resulting error identifies whether permission, read, or file-locking behavior is involved.

Written by the indexing model from the issue text.