hack/test: allow ALPINE_VERSION to be set from env

Signed-off-by: Sebastiaan van Stijn <[email protected]>
(cherry picked from commit 295c899)
Signed-off-by: Sebastiaan van Stijn <[email protected]>

Author: thaJeztah

hack/test

@@ -3,6 +3,7 @@
 . $(dirname $0)/util
 set -eu -o pipefail
 
+: "${ALPINE_VERSION=}"
 : "${GO_VERSION=}"
 : "${HTTP_PROXY=}"
 : "${HTTPS_PROXY=}"
@@ -77,6 +78,7 @@ if [[ "$GOBUILDFLAGS" == *"-race"* ]]; then
 fi
 
 buildxCmd build $cacheFromFlags \
+  --build-arg ALPINE_VERSION \
   --build-arg GO_VERSION \
   --build-arg BUILDKITD_TAGS \
   --build-arg HTTP_PROXY \