### Apache Airflow version

2.2.3 (latest released)

### What happened

When I modify airflow.cfg about default webserver listening port to 8000,  then start with "airflow standalone"

A error will be printed:
 webserver | [2021-12-25 22:20:08 +0800] [16173] [ERROR] Connection in use: ('0.0.0.0', 8080)
 webserver | [2021-12-25 22:20:08 +0800] [16173] [ERROR] Retrying in 1 second.
 webserver | [2021-12-25 22:20:10 +0800] [16173] [ERROR] Connection in use: ('0.0.0.0', 8080)
 webserver | [2021-12-25 22:20:10 +0800] [16173] [ERROR] Retrying in 1 second.
 webserver | [2021-12-25 22:20:11 +0800] [16173] [ERROR] Connection in use: ('0.0.0.0', 8080)
 webserver | [2021-12-25 22:20:11 +0800] [16173] [ERROR] Retrying in 1 second.
 webserver | [2021-12-25 22:20:12 +0800] [16173] [ERROR] Connection in use: ('0.0.0.0', 8080)
 webserver | [2021-12-25 22:20:12 +0800] [16173] [ERROR] Retrying in 1 second.
 webserver | [2021-12-25 22:20:13 +0800] [16173] [ERROR] Connection in use: ('0.0.0.0', 8080)
 webserver | [2021-12-25 22:20:13 +0800] [16173] [ERROR] Retrying in 1 second.
 webserver | [2021-12-25 22:20:14 +0800] [16173] [ERROR] Can't connect to ('0.0.0.0', 8080)

Source code position,
https://github.com/apache/airflow/blob/main/airflow/cli/commands/standalone_command.py line 209, function is_ready
        return self.port_open(**8080**) and self.job_running(SchedulerJob) and self.job_running(TriggererJob)

force the port to 8080, it's wrong.

### What you expected to happen

_No response_

### How to reproduce

_No response_

### Operating System

All System

### Versions of Apache Airflow Providers

_No response_

### Deployment

Other

### Deployment details

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

airflow/cli/commands/standalone_command.py
"""
        Prints an error message to the console (this is the same as
        print_output but with the text red)
        """
        self.print_output(name, colored(output, "red"))
    def calculate_env(self):
        """
        Works out the environment variables needed to run subprocesses.
        We override some settings as part of being standalone.
        """
        env = dict(os.environ)
        
        if conf.get("core", "executor") not in [
            executor_constants.LOCAL_EXECUTOR,
            executor_constants.SEQUENTIAL_EXECUTOR,
        ]:
            if "sqlite" in conf.get("core", "sql_alchemy_conn"):
                self.print_output("standalone", "Forcing executor to SequentialExecutor")
                env["AIRFLOW__CORE__EXECUTOR"] = executor_constants.SEQUENTIAL_EXECUTOR
            else:
                self.print_output("standalone", "Forcing executor to LocalExecutor")
                env["AIRFLOW__CORE__EXECUTOR"] = executor_constants.LOCAL_EXECUTOR
        return env
    def initialize_database(self):