[BUG] config.items and config.get do not properly handle fields with datetime values

Description
function config.items internally returns datetime objects that are not properly handled by outputters and/or salt-api.

Setup
just a master and a minion.

• on-prem machine
• VM (Virtualbox)
• VM running on a cloud service, please be explicit and add details
• container (Kubernetes, Docker, containerd, etc. please specify)
• or a combination, please be explicit
• jails if it is FreeBSD
• classic packaging
• onedir packaging
• used bootstrap to install

Steps to Reproduce the behavior
Issue command config.get schedule
also for config.items, but that one has much more unrelated output

Expected behavior
time-related fields are properly reported.
notably fields: schedule.__mine_interval._next_fire_time, schedule.__mine_interval._next_scheduled_fire_time and schedule.__mine_interval._last_run

observed behaviour:

• with salt --out json
  the fields are reported as strings, e.g. datetime.datetime(2022, 9, 17, 16, 20, 9, 840987)
• with salt --out yaml
  the fields are reported as strings, e.g. 2022-09-17 15:04:42.239934
• with salt --out nested (which is also the default)
  the fields are reported as empty values
• with salt-api
  the server crashes on the handling of this api call and only a "500 internal error" is reported
  this is of course the most important observation, as it makes config.items completely unusable in this context.

Versions Report

Salt Version:
          Salt: 3004.2
 
Dependency Versions:
          cffi: Not Installed
      cherrypy: unknown
      dateutil: 2.8.1
     docker-py: Not Installed
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 2.11.3
       libgit2: Not Installed
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.0.0
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     pycparser: Not Installed
      pycrypto: Not Installed
  pycryptodome: 3.9.7
        pygit2: Not Installed
        Python: 3.9.2 (default, Feb 28 2021, 17:03:44)
  python-gnupg: Not Installed
        PyYAML: 5.3.1
         PyZMQ: 20.0.0
         smmap: Not Installed
       timelib: Not Installed
       Tornado: 4.5.3
           ZMQ: 4.3.4
 
System Versions:
          dist: debian 11 bullseye
        locale: utf-8
       machine: x86_64
       release: 5.10.0-15-amd64
        system: Linux
       version: Debian GNU/Linux 11 bullseye

Additional
there might be other apis that have a similar behaviour

Start by reproducing config.get schedule and config.items with the JSON, YAML, and nested outputters, then inspect the configuration handling, outputter serialization, and salt-api paths mentioned in the report. Trace how the datetime fields are converted at each boundary. Done means the listed schedule fields are represented correctly by all three outputters and the salt-api request no longer returns a 500 error.