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/commit_sweep_resolver.go

@@ -165,9 +165,7 @@ func (c *commitSweepResolver) getCommitTxConfHeight() (uint32, error) {
 // returned.
 //
 // NOTE: This function MUST be run as a goroutine.
-//
-//nolint:funlen
-func (c *commitSweepResolver) Resolve(_ bool) (ContractResolver, error) {
+func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
 	// If we're already resolved, then we can exit early.
 	if c.resolved {
 		return nil, nil