build: fix quiet default for make builds

The Makefile documents quiet output unless V=1 and sets `V ?= 0`, but
it forwards `V=$(V)` to the gyp-generated makefile, which tests
`ifdef V`. "0" is a non-empty value there, so every make build has
printed the full compiler command lines regardless. Default V to empty
so the sub-make takes its quiet_ rules; `make V=1` and V=1 in the
environment stay verbose, and the ninja and cpplint checks already
compare against 1.

Refs: #26740
Refs: nodejs/build#4419
Signed-off-by: Shelley Vohr <shelley.vohr@gmail.com>
PR-URL: #65826
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

Author: codebytere

Makefile

@@ -96,7 +96,7 @@ BUILD_RELEASE_FLAGS ?= $(BUILD_DOWNLOAD_FLAGS) $(BUILD_INTL_FLAGS)
 
 # Default to quiet/pretty builds.
 # To do verbose builds, run `make V=1` or set the V environment variable.
-V ?= 0
+V ?=
 
 # Use -e to double check in case it's a broken link
 available-node = \