expvar: add Delete function

Adds a `Delete` function to the expvar package to remove a named
exported variable. Calls `Map.Delete`.

Closes golang#73814

Author: mhamza15

src/expvar/expvar.go

@@ -316,6 +316,11 @@ func Publish(name string, v Var) {
 	slices.Sort(vars.keys)
 }
 
+// Delete removes a named exported variable.
+func Delete(name string) {
+	vars.Delete(name)
+}
+
 // Get retrieves a named exported variable. It returns nil if the name has
 // not been registered.
 func Get(name string) Var {