Disable arm7 builds (#7037)

* Disable arm7 builds

As arm6 works on arm7 platforms with no noticeable performance difference

* 386

Makefile

@@ -335,7 +335,7 @@ release-linux:
 	@hash xgo > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
 		$(GO) get -u src.techknowlogick.com/xgo; \
 	fi
-	xgo -dest $(DIST)/binaries -tags 'netgo osusergo $(TAGS)' -ldflags '-linkmode external -extldflags "-static" $(LDFLAGS)' -targets 'linux/*' -out gitea-$(VERSION) .
+	xgo -dest $(DIST)/binaries -tags 'netgo osusergo $(TAGS)' -ldflags '-linkmode external -extldflags "-static" $(LDFLAGS)' -targets 'linux/amd64,linux/386,linux/arm-5,linux/arm-6,linux/arm64,linux/mips64le,linux/mips,linux/mipsle' -out gitea-$(VERSION) .
 ifeq ($(CI),drone)
 	cp /build/* $(DIST)/binaries
 endif