Always regenerate go.work file (#20842)

We flip the default mode to always regenerate the file,
and expose an option to ignore if it exists.

```release-note
NONE
```

Makefile

@@ -414,7 +414,7 @@ endif
 setup-go-work: export BUILD_ENTERPRISE_READY := $(BUILD_ENTERPRISE_READY)
 setup-go-work: export BUILD_BOARDS := $(BUILD_BOARDS)
 setup-go-work: ## Sets up your go.work file
-	./scripts/setup_go_work.sh
+	./scripts/setup_go_work.sh $(IGNORE_GO_WORK_IF_EXISTS)
 
 check-style: golangci-lint plugin-checker vet ## Runs style/lint checks
 

scripts/setup_go_work.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-if [[ ! -f "go.work" ]] ;
+if [[ $1 != "true" ]] ;
 then
     echo "Creating a go.work file"