platform_transition_test appears to break RUNPATH

Hello

I am using ``platform_transition_test`` on a C++ test binary.
When executing the test remotely it fails because it cannot find the shared libraries in _solib_aarch64 (referenced in the binary using RUNPATH)

The issue appears to be that the "symlink" action does not guarantee to produce a symlink remotely and therefore
our buildbarn worker gets a copy instead, and this breaks RUNPATH resolution (the RUNPATH uses relative locations)

I can work around it in my case by outputting a wrapper bash script that exec's the test binary. Basically changing the symlink action to be this instead

```py
ctx.actions.write(
new_executable,
content = """#!/bin/bash
exec {}
""".format(original_executable.short_path),
is_executable = True,

```

However I would like to discuss what could be a permanent solution to this problem

Start by reading and running platform_transition_test with a remotely executed C++ test binary, then inspect the symlink action described in the issue. Reproduce the failure involving _solib_aarch64 and relative RUNPATH resolution; done means the remote test can locate its shared libraries without relying on an unconfirmed symlink or an ad hoc wrapper.

Written by the indexing model from the issue text.