CI: Skip pushing wasm builder unless required

The `push-builder` target will now check if the tag is already
available via a test with `docker pull`. It will only build and
push if the image is not available remotely.

Signed-off-by: Patrick East <east.patrick@gmail.com>

Makefile

@@ -314,7 +314,7 @@ push-image: docker-login image-quick push
 
 .PHONY: push-wasm-builder-image
 push-wasm-builder-image: docker-login
-	$(MAKE) -C wasm builder push-builder
+	$(MAKE) -C wasm push-builder
 
 .PHONY: deploy-ci
 deploy-ci: push-image tag-edge push-edge push-binary-edge

wasm/Makefile

@@ -39,7 +39,7 @@ ensure-builder:
 
 .PHONY: push-builder
 push-builder:
-	$(DOCKER) push $(WASM_BUILDER_IMAGE)
+	$(DOCKER) pull $(WASM_BUILDER_IMAGE) || ($(MAKE) builder && $(DOCKER) push $(WASM_BUILDER_IMAGE))
 
 .PHONY: build
 build: