package/mender-artifact: drop custom GOFLAGS

Now that we have switched to the go.mod integration, all Go packages
are built with -mod=vendor, so there's no need to have custom GOFLAGS
in mender-artifact.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/mender-artifact/mender-artifact.mk

@@ -31,14 +31,6 @@ HOST_MENDER_ARTIFACT_LICENSE_FILES = \
 
 HOST_MENDER_ARTIFACT_DEPENDENCIES = host-xz
 
-# By default, go will attempt to download needed modules before building, which
-# is not desirable. This behavior also causes permission issues when cleaning,
-# as go downloads modules as read-only by default. Because mender-artifact
-# includes the modules in the vendor directory, mod=vendor prevents the package
-# from downloading the go modules during the build process and prevents
-# permission issues when cleaning.
-HOST_MENDER_ARTIFACT_GO_ENV = GOFLAGS="-mod=vendor"
-
 HOST_MENDER_ARTIFACT_LDFLAGS = -X main.Version=$(HOST_MENDER_ARTIFACT_VERSION)
 
 HOST_MENDER_ARTIFACT_BUILD_TARGETS = cli/mender-artifact