Bump block header protocol version

Alonzo will now broadcast 7.2 (even though we are actually moving to
7.0, this is to distinguish from other versions of the node that are
broadcasting major version 7). Babbage will now broadcast 7.0, the
version that we are actually moving to.

cardano-node/src/Cardano/Node/Protocol/Cardano.hs

@@ -198,7 +198,12 @@ mkSomeConsensusProtocolCardano NodeByronProtocolConfiguration {
           -- version that this node will declare that it understands, when it
           -- is in the Alonzo era. That is, it is the version of protocol
           -- /after/ Alonzo, i.e. Babbage.
-          alonzoProtVer = ProtVer 7 1,
+	  --
+	  -- NOTE that we are not actually transitioning to version 7.2,
+	  -- this is a HACK so that we can distinguish between others
+	  -- versions of the node that are broadcasting major version 7.
+	  -- We intentionally broadcast 7.0 starting in Babbage.
+          alonzoProtVer = ProtVer 7 2,
           alonzoMaxTxCapacityOverrides =
             TxLimits.mkOverrides TxLimits.noOverridesMeasure
         }
@@ -207,7 +212,7 @@ mkSomeConsensusProtocolCardano NodeByronProtocolConfiguration {
           -- version that this node will declare that it understands, when it
           -- is in the Babbage era. Since Babbage is currently the last known
           -- protocol version then this is also the Babbage protocol version.
-          Praos.babbageProtVer = ProtVer 7 1,
+          Praos.babbageProtVer = ProtVer 7 0,
           Praos.babbageMaxTxCapacityOverrides =
             TxLimits.mkOverrides TxLimits.noOverridesMeasure
         }