fix(engine): Resolve issue with ExecuteWithResults function not returning expected results

[boy-hack]

When attempting to use the ExecuteWithResults function, users were finding that the function was not returning the expected results. This fix addresses the root cause of this problem.

example code

	v := nuclei.VerbosityOptions{
		Verbose:       true,
		Silent:        false,
		Debug:         true,
		DebugRequest:  false,
		DebugResponse: false,
		ShowVarDump:   false,
	}
	ne, err := nuclei.NewNucleiEngine(
		nuclei.WithVerbosity(v),
	)
	if err != nil {
		panic(err)
	}
	defer ne.Close()
	httpProvider := provider.NewSimpleInputProvider()
	httpProvider.Set("https://x.hacking8.com")

	filename := "1.yaml"
	data, err := ioutil.ReadFile(filename)
	if err != nil {
		panic(err)
	}
	poc, err := ne.ParseTemplate(data)
	if err != nil {
		panic(err)
	}
	pocList := []*templates.Template{
		poc,
	}
	engine := ne.Engine()
	engine.ExecuteWithResults(context.Background(), pocList, httpProvider, func(event *output.ResultEvent) {
		fmt.Println(1)
		fmt.Println(event)
	})
	engine.WorkPool().Wait()

Proposed changes

Checklist

• Pull request is created against the dev branch
• All checks passed (lint, unit/integration/regression tests etc.) with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[tarunKoyalwar]

thanks for fixing this issue @boy-hack