chore(repo): remove dead code and useless tests (#3375)

fluxer_gateway/Makefile

@@ -2,7 +2,7 @@
 
 GATEWAY_TOOL := cargo run --locked --quiet --manifest-path ../tools/ci/Cargo.toml -- gateway --step
 
-.PHONY: all fmt fmt-check lint typecheck test check compile clean bench
+.PHONY: all fmt fmt-check lint typecheck test check compile clean
 
 all: check
 
@@ -29,6 +29,3 @@ compile:
 
 clean:
 	@$(GATEWAY_TOOL) clean
-
-bench:
-	@$(GATEWAY_TOOL) bench