grandpa: remove light-client specific block import pipeline (#7546)

* grandpa: remove light-client specific block import

* consensus, network: remove finality proofs

substrate/bin/node/testing/src/bench.rs

@@ -695,7 +695,6 @@ impl BenchContext {
 					clear_justification_requests: false,
 					needs_justification: false,
 					bad_justification: false,
-					needs_finality_proof: false,
 					is_new_best: true,
 				}
 			)