No need for ` mkdir -p -$(CARGO_TARGET_DIR)` in Makefile

[dilyanpalauzov]

In Makefile the target $(CARGO_TARGET_DIR): mkdir -p $@ is not necessary. With this change:

diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -49,11 +49,8 @@ bin:
        mkdir -p $@
 
-$(CARGO_TARGET_DIR):
-       mkdir -p $@
-
 .PHONY: build
 build: bin/netavark
 
-bin/netavark: $(SOURCES) bin $(CARGO_TARGET_DIR)
+bin/netavark: $(SOURCES) bin
        $(CARGO) build $(release)
        cp $(CARGO_TARGET_DIR)/$(profile)/netavark bin/netavark

CARGO_TARGET_DIR=abc make, make CARGO_TARGET_DIR=def and make do create the target directory as expected using cargo 1.89.0.