contractcourt: remove the immediate param used in Resolve

This `immediate` flag was added as a hack so during a restart, the
pending resolvers would offer the inputs to the sweeper and ask it to
sweep them immediately. This is no longer need due to `blockbeat`, as
now during restart, a block is always sent to all subsystems via the
flow `ChainArb` -> `ChannelArb` -> resolvers -> sweeper. Thus, when
there are pending inputs offered, they will be processed by the sweeper
immediately.

contractcourt/anchor_resolver.go

@@ -84,7 +84,7 @@ func (c *anchorResolver) ResolverKey() []byte {
 }
 
 // Resolve offers the anchor output to the sweeper and waits for it to be swept.
-func (c *anchorResolver) Resolve(_ bool) (ContractResolver, error) {
+func (c *anchorResolver) Resolve() (ContractResolver, error) {
 	// Attempt to update the sweep parameters to the post-confirmation
 	// situation. We don't want to force sweep anymore, because the anchor
 	// lost its special purpose to get the commitment confirmed. It is just