text: Title: Labeled environments cannot use runners from provisioned plugins
  Body: ## Issue
  
  When a tox environment has a `runner` derived from a plugin that is named in the `requires` key, the environment cannot appear in a top-level label expression.
  
  See minimal reproducer: https://github.com/masenf/tox-label-provision-plugin-runner
  
  ```ini
  [tox]
  requires = foo-runner
  labels =
      foo = bar, baz
  envlist = bar, baz
  
  [testenv:{bar,baz}]
  runner = foo
  ```
  
  running `tox` uses the `envlist`, which works fine.
  
  running `tox -m foo` uses the `label` foo, and blows up before passing off control to the provisioned tox
  
  ## Environment
  
  Provide at least:
  
  - OS: ubuntu 20.04
  - `pip list` of the host Python where `tox` is installed:
  
  ```console
  cachetools==5.3.0
  chardet==5.1.0
  colorama==0.4.6
  distlib==0.3.6
  filelock==3.9.0
  packaging==23.0
  platformdirs==3.0.0
  pluggy==1.0.0
  pyproject-api==1.5.0
  tomli==2.0.1
  tox==4.4.4
  virtualenv==20.19.0
  ```
  
  ## Output of running tox
  
  Provide the output of `tox -rvv`:
  
  ```console
  tox -rvv -m foo
  ROOT: 1297 W will run in automatically provisioned tox, host /home/mfurer/.pytools/bin/python is missing [requires (has)]: foo-runner [tox/provision.py:125]
  Traceback (most recent call last):
    File "/home/mfurer/.pytools/bin/tox", line 8, in <module>
      sys.exit(run())
    File "/home/mfurer/.pytools/lib/python3.8/site-packages/tox/run.py", line 19, in run
      result = main(sys.argv[1:] if args is None else args)
    File "/home/mfurer/.pytools/lib/python3.8/site-packages/tox/run.py", line 41, in main
      result = provision(state)
    File "/home/mfurer/.pytools/lib/python3.8/site-packages/tox/provision.py", line 126, in provision
      return run_provision(provision_tox_env, state)
    File "/home/mfurer/.pytools/lib/python3.8/site-packages/tox/provision.py", line 144, in run_provision
      tox_env: PythonRun = cast(PythonRun, state.envs[name])
    File "/home/mfurer/.pytools/lib/python3.8/site-packages/tox/session/env_select.py", line 337, in __getitem__
      return self._defined_envs[item].env
    File "/home/mfurer/.pytools/lib/python3.8/site-packages/tox/session/env_select.py", line 233, in _defined_envs
      self._mark_active()
    File "/home/mfurer/.pytools/lib/python3.8/site-packages/tox/session/env_select.py", line 321, in _mark_active
      self._defined_envs_[env_name].is_active = True
  KeyError: 'bar'
  ```
  
  ## Minimal example
  
  https://github.com/masenf/tox-label-provision-plugin-runner
  