Partially revert "build-suggestions/4.7: Raise *_min to 4.y.9999"

This partially reverts commit f190365, openshift#732.

The vSphere hostname thing is verified fixed in 4.7 [1].  And the
vSphere HW thing [2].  A new-in-4.7.3 OVN thing that we'd been on the
fence about blocking on [3] should also be fixed [4].

4.6.4 will fix an issue with non-control-plane UPI vSphere
MachineConfigPools getting stuck if you update to 4.7 while they're
churning a 4.6 udpate [5], so we're setting the 4.6 floor at 4.6.24.
Folks on older 4.6 will have to get to at least 4.6.24 to pick up that
fix before they can go to 4.7.

[1]: https://bugzilla.redhat.com/show_bug.cgi?id=1943143#c4
[2]: https://bugzilla.redhat.com/show_bug.cgi?id=1941246#c6
[3]: https://bugzilla.redhat.com/show_bug.cgi?id=1940498#c12
[4]: https://bugzilla.redhat.com/show_bug.cgi?id=1942702#c1
[5]: https://bugzilla.redhat.com/show_bug.cgi?id=1940585#c18

build-suggestions/4.7.yaml

@@ -2,10 +2,10 @@
 # If you specify an arch it must have the full set of values
 ---
 default:
-  minor_min: 4.6.9999
+  minor_min: 4.6.24
   minor_max: 4.6.9999
   minor_block_list: []
-  z_min: 4.7.9999
+  z_min: 4.7.0
   z_max: 4.7.9999
   z_block_list: []
 # s390x: