Remove schema migrations for v28 and earlier (#9031)

With LH v8.1.3 supporting Fulu-on-Gnosis, we no longer need these DB migrations. All Lighthouse nodes running in prod will soon be updated to LH v8.0.0+ and schema v28+.

This PR helps with Gloas fork choice changes, by allowing us to avoid updating old schema migrations when adding V29 for Gloas:

- https://github.com/sigp/lighthouse/pull/9025


  


Co-Authored-By: Michael Sproul <michael@sigmaprime.io>

beacon_node/store/src/database/leveldb_impl.rs

@@ -186,10 +186,8 @@ impl<E: EthSpec> LevelDB<E> {
             )
         };
 
-        for (start_key, end_key) in [
-            endpoints(DBColumn::BeaconState),
-            endpoints(DBColumn::BeaconStateSummary),
-        ] {
+        {
+            let (start_key, end_key) = endpoints(DBColumn::BeaconStateHotSummary);
             self.db.compact(&start_key, &end_key);
         }