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/discovery.rs

@@ -222,8 +222,9 @@ pub enum Error {
         PythonSource,
     ),
 
-    /// An error was encountered when interacting with a managed Python installation.
-    #[error(transparent)]
+    /// An error was encountered while trying to find a managed Python installation matching the
+    /// current platform.
+    #[error("Failed to discover managed Python installations")]
     ManagedPython(#[from] crate::managed::Error),
 
     /// An error was encountered when inspecting a virtual environment.