Solver executables - permission and packaging issues

[AdamZsofi]

Issues with owner only permissions:

In SolverInstallers (e.g., BitwuzlaSmtLibSolverInstaller) in the installSolver method setExecutable is called with ownerOnly = true.
This is usually enough, but e.g., on docker it might cause child processes failing to start.

Typical output caused by this issue:
server: WARNING: Failed to start process server: java.io.IOException: error=13, Permission denied
( output.txt )

I needed a quick-fix, which was manually giving executable rights (chmod +x) to all of the installed solver executables.

We should change this parameter to false to fix.

Issues with legacy z3 in CI

Some z3 libraries are not added to the Theta.zip file generated by the CI for releases.