DRep pulser property test needs fixing

[lehins]

Due to changes in #4253 the DRep pulser property test was broken and had to be temporarily disabled:

cardano-ledger/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Trace/DrepCertTx.hs

Lines 173 to 180 in 54dc232

	testGroup "DRep property traces" []
	-- FIXME: re-enable
	_drepTree :: TestTree
	_drepTree =
	testGroup
	"DRep property traces"
	[ testProperty

This test needs to be fixed and re-enabled

[lehins]

Fixed in #4389