cloe-launch doesn't export LD_LIBRARY_PATH variables

[cassava]

The latest version of cloe-launch uses the Conan 2.0 compatible generator VirtualRunEnv.
Unfortunately, it looks like test conanfiles that don't specify these lines

class CloeLaunchProfile(ConanFile):
    python_requires = "cloe-launch-profile/[>=0.20.0]@cloe/develop"
    python_requires_extend = "cloe-launch-profile.Base"

are not exporting LD_LIBRARY_PATH variables.

This is not by design.

Reproduce:

1. Ensure all packages are available.
2. Ensure that cloe-launch -vv shell tests/conanfile_*.py works for any particular test.
   That is, LD_LIBRARY_PATH is in the exported environment.
3. Exit environment
4. Remove the python requires lines from the test profile.
5. Check that repeat run cloe-launch does not export LD_LIBRARY_PATH variable.