dnf5: Don't output to a PTY

If DNF 5 sees an "interactive" TTY on stdout, it will try to draw
progress bars and cause the Mock logs to be garbled:
fedora-copr/copr#3040. A simple fix is to have
DNF 5 output to a pipe instead of a PTY.

I'm not sure why output is collected via a PTY from yum/dnf (seems to
start from commit 99ca2fa), but it's probably no longer needed
for DNF 5?

mock/py/mockbuild/package_manager.py

@@ -758,5 +758,9 @@ class Dnf5(Dnf):
     """
     name = 'dnf5'
     place_common_opts_after = True
+
+    def execute(self, *args, **kwargs):
+        return super(Dnf, self).execute(*args, **{"pty": False, **kwargs})
+
     def update(self, *args, **_kwargs):
         return self.execute('upgrade', *args)