Build: Remove assets/compiled.go before build

Makes sure the compiled result is not included in itself again every
time. After a while this leads to memory consumption of multiple GB
during build and a bloated binary. 😬

Makefile

@@ -1,4 +1,5 @@
 build:
+	rm -f assets/compiled.go
 	go generate -v
 	go install -v
 	go build -v -ldflags "-X github.com/flownative/localbeach/pkg/version.Version=dev" -o beach