Quiet ar with ARFLAGS rather than > null

`ARFLAGS` is an implicit variable in GNU `make` (the `README` _specifies GNU_ `make`) and defaulted verbosely, so un-verbose-fy it is the more direct *and platform-agnostic* way to quiet `ar`.

Makefile

@@ -14,6 +14,7 @@ CPPFLAGS := -Iinclude $(CPPFLAGS)
 CFLAGS := -g -O2 -std=c99 -Wall -Werror -Wextra -Wpedantic -Wundef -Wconversion -Wno-missing-braces -fPIC -fvisibility=hidden $(CFLAGS)
 CC ?= cc
 AR ?= ar
+ARFLAGS ?= -r$(V0:1=v)
 WASI_SDK_PATH := /opt/wasi-sdk
 
 MAKEDIRS ?= mkdir -p
@@ -37,7 +38,7 @@ build/libprism.$(SOEXT): $(SHARED_OBJECTS)
 
 build/libprism.a: $(STATIC_OBJECTS)
 	$(ECHO) "building $@ with $(AR)"
-	$(Q) $(AR) $(ARFLAGS) $@ $(STATIC_OBJECTS) $(Q1:0=>/dev/null)
+	$(Q) $(AR) $(ARFLAGS) $@ $(STATIC_OBJECTS)
 
 javascript/src/prism.wasm: Makefile $(SOURCES) $(HEADERS)
 	$(ECHO) "building $@"