cockpit.spec: drop RHEL build hanging workarounds
cockpit.spec: drop RHEL build hanging workarounds

We managed to see a i686 build hang in the wild, when trying to build on
Fedora.  That was a combination of two bugs (#17307, #17315).

It should now be generally impossible for the tests to hang.  Let's
remove the workaround.

cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpit-project/cockpit,martinpitt/cockpit,mvollmer/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,mvollmer/cockpit,mvollmer/cockpit,cockpit-project/cockpit,martinpitt/cockpit,mvollmer/cockpit,martinpitt/cockpit,mvollmer/cockpit