Remove 386 and test

Author: ChakshuGautam

Makefile

@@ -10,7 +10,7 @@ PREV_TS_IMAGE="timescale/timescaledb:$(PREV_TS_VERSION)-pg$(PG_VER_NUMBER)$(PREV
 PREV_IMAGE=$(shell if docker pull $(PREV_TS_IMAGE) >/dev/null; then echo "$(PREV_TS_IMAGE)"; else echo "postgres:$(PG_VER_NUMBER)-alpine"; fi )
 # Beta releases should not be tagged as latest, so BETA is used to track.
 BETA=$(findstring rc,$(TS_VERSION))
-PLATFORM=linux/386
+PLATFORM=linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
 
 # PUSH_MULTI can be set to nothing for dry-run without pushing during multi-arch build
 PUSH_MULTI=--push