minor #20386 [Validator] [MacAddress] Add a missing value for type option (MrYamous)

This PR was merged into the 7.1 branch.

Discussion
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[Validator] [MacAddress] Add a missing value for `type` option

It looks like a value accidentally disappeared during a commit to sort them in alphabetical order

Commits
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8ed98d3 add a missing value in MacAdress constraint

Author: javiereguiluz

reference/constraints/MacAddress.rst

@@ -132,6 +132,7 @@ Parameter                         Allowed MAC addresses
 ``multicast_no_broadcast``        Only multicast except broadcast
 ``unicast_all``                   Only unicast
 ``universal_all``                 Only universal
+``universal_unicast``             Only universal and unicast
 ``universal_multicast``           Only universal and multicast
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