chore: cache modd tool

Makefile

@@ -15,8 +15,8 @@ SHELL := bash
 
 build: build-edge-cli build-client-sdk-test-app
 
-watch:
-	go run -mod=readonly github.com/cortesi/modd/cmd/modd@latest
+watch: tools/modd/bin/modd
+	tools/modd/bin/modd
 
 .PHONY: test
 test: test-go
@@ -101,4 +101,8 @@ tools/gitea-release/bin/gitea-release.sh:
 tools/yq/bin/yq:
 	mkdir -p tools/yq/bin
 	curl -L --output tools/yq/bin/yq https://github.com/mikefarah/yq/releases/download/v4.31.1/yq_linux_amd64
-	chmod +x tools/yq/bin/yq
+	chmod +x tools/yq/bin/yq
+
+tools/modd/bin/modd:
+	mkdir -p tools/modd/bin
+	GOBIN=$(PWD)/tools/modd/bin go install -mod=readonly github.com/cortesi/modd/cmd/modd@latest