Identify buildroot package management earlier

It's useful to see the tooling used for buildroot installation before
the installation begins.

Author: praiskup

mock/py/mockbuild/backend.py

@@ -261,8 +261,6 @@ def build(self, srpm, timeout, check=True, spec=None):
         self.plugins.call_hooks('earlyprebuild')
         # intentionally we do not call bootstrap hook here - it does not have sense
 
-        self.buildroot.pkg_manager.log_package_management_packages()
-
         baserpm = os.path.basename(srpm)
 
         buildstate = "build phase for %s" % baserpm

mock/py/mockbuild/buildroot.py

@@ -308,6 +308,9 @@ def _init(self, prebuild):
         self._setup_resolver_config()
         self._setup_katello_ca()
 
+        if prebuild:
+            self.pkg_manager.log_package_management_packages()
+
         if not self.chroot_was_initialized:
             self._setup_dbus_uuid()
             self._init_aux_files()

releng/release-notes-next/package-management-logging.feature

@@ -0,0 +1,3 @@
+The info about package management tooling used to install the target buildroot
+has been updated to provide the info earlier, before the buildroot installation
+happens.  Mock newly informs also about dnf5 presence.