make the error message clearer when running distroless containers (#13549)

Previously you could get a confusing error message like this:

```
$ docker run ghcr.io/astral-sh/uv run python
error: Could not read ELF interpreter from any of the following paths: /bin/sh, /usr/bin/env, /bin/dash, /bin/ls
```

Now the error message is better:

```
error: Failed to discover managed Python installations
  Caused by: Failed to determine the libc used on the current platform
  Caused by: Failed to find any common binaries to determine libc from: /bin/sh, /usr/bin/env, /bin/dash, /bin/ls
```

See https://github.com/astral-sh/uv/issues/8635.

---------

Co-authored-by: konsti <konstin@mailbox.org>
Co-authored-by: Zanie Blue <contact@zanie.dev>

crates/uv-python/src/downloads.rs

@@ -91,7 +91,7 @@ pub enum Error {
     NoDownloadFound(PythonDownloadRequest),
     #[error("A mirror was provided via `{0}`, but the URL does not match the expected format: {0}")]
     Mirror(&'static str, &'static str),
-    #[error(transparent)]
+    #[error("Failed to determine the libc used on the current platform")]
     LibcDetection(#[from] LibcDetectionError),
     #[error("Remote Python downloads JSON is not yet supported, please use a local path")]
     RemoteJSONNotSupported,