s/Get(Master|Replica)X/Get\1/g (#29520)

Drop the legacy `X` suffix from `GetMasterX` and `GetReplicaX`. The
presence of the suffix suggests there's a `non-X` version: but in fact
we migrated these away a long time ago, so remove the cognitive
overhead.

As an aside, this additionally helps avoid trip up LLMs that interpret
this as "something to fix".

server/channels/store/sqlstore/sqlx_wrapper.go

@@ -30,8 +30,8 @@ func NewStoreTestWrapper(orig *SqlStore) *StoreTestWrapper {
 	return &StoreTestWrapper{orig}
 }
 
-func (w *StoreTestWrapper) GetMasterX() storetest.SqlXExecutor {
-	return w.orig.GetMasterX()
+func (w *StoreTestWrapper) GetMaster() storetest.SqlXExecutor {
+	return w.orig.GetMaster()
 }
 
 func (w *StoreTestWrapper) DriverName() string {