空闲时释放服务器内存空间

I have a code that has this structure:

package main

import (
    "html/template"
    "net/http"
    "log"
)

func main() {
    http.HandleFunc("/",myFunction)
    http.HandleFunc("/route2",mySecondFunction)
    http.HandleFunc("/route3",myThirdFunction)
    http.ListenAndServe(":8080",nil)
}

func check(err error){
    if err != nil{
        log.Fatal(err)
    }
}

func myFunction(w http.ResponseWriter, r *http.Request){
    if r.Method == "GET"{
        t,err := template.ParseFiles("request.html")
        check(err)
        t.Execute(w,nil)
    }
}

This code simply creates a server with whatever it has in request.html file and it runs in localhost: 8080, see the routes I set in http.HandleFunc("/", myFunction).

I could see that in task manager, even when the server was idle, memory usage never decreased, only increasing according to the amount of calls I made to the server.

Init state:

After some requests:

And this working set never decreased

How can I do to free up the memory that has already been used and at the same time not disable the server?