text: Title: Load elmo-constituency-parser from archive failed
  Body: ## Checklist
  
  <!-- To check an item on the list replace [ ] with [x]. -->
  
  - [ ] I have verified that the issue exists against the `main` branch of AllenNLP.
  - [ ] I have read the relevant section in the [contribution guide](https://github.com/allenai/allennlp/blob/main/CONTRIBUTING.md#bug-fixes-and-new-features) on reporting bugs.
  - [x] I have checked the [issues list](https://github.com/allenai/allennlp/issues) for similar or identical bug reports.
  - [x] I have checked the [pull requests list](https://github.com/allenai/allennlp/pulls) for existing proposed fixes.
  - [ ] I have checked the [CHANGELOG](https://github.com/allenai/allennlp/blob/main/CHANGELOG.md) and the [commit log](https://github.com/allenai/allennlp/commits/main) to find out if the bug was already fixed in the main branch.
  - [x] I have included in the "Description" section below a traceback from any exceptions related to this bug.
  - [ ] I have included in the "Related issues or possible duplicates" section beloew all related issues and possible duplicate issues (If there are none, check this box anyway).
  - [x] I have included in the "Environment" section below the name of the operating system and Python version that I was using when I discovered this bug.
  - [ ] I have included in the "Environment" section below the output of `pip freeze`.
  - [ ] I have included in the "Steps to reproduce" section below a minimally reproducible example.
  
  
  ## Description
  
  <!-- Please provide a clear and concise description of what the bug is here. -->
  
      archive = load_archive(
          "elmo-constituency-parser-2018.03.14.tar.gz"
      )
      predictor = Predictor.from_archive(archive, 'constituency-parser')
  
      predictor.predict_json({"sentence": "This is a sentence to be predicted!"})
  
  <details>
  <summary><b>Python traceback:</b></summary>
  <p>
  
  <!-- Paste the traceback from any exception (if there was one) in between the next two lines below -->
  ```
  Traceback (most recent call last):
    File "E:\Chuan\Documents\GitHub\allennlp\allennlp\models\archival.py", line 232, in load_archive
      dataset_reader, validation_dataset_reader = _load_dataset_readers(
    File "E:\Chuan\Documents\GitHub\allennlp\allennlp\models\archival.py", line 268, in _load_dataset_readers
      dataset_reader = DatasetReader.from_params(
    File "E:\Chuan\Documents\GitHub\allennlp\allennlp\common\from_params.py", line 638, in from_params
      subclass, constructor_name = as_registrable.resolve_class_name(choice)
    File "E:\Chuan\Documents\GitHub\allennlp\allennlp\common\registrable.py", line 207, in resolve_class_name
      raise ConfigurationError(
  allennlp.common.checks.ConfigurationError: 'ptb_trees' is not a registered name for 'DatasetReader'. If your registered class comes from custom code, you'll need to import the corresponding modules. If you're using AllenNLP from the command-line, this is done by using the '--include-package' flag, or by specifying your imports in a '.allennlp_plugins' file. Alternatively, you can specify your choices using fully-qualified paths, e.g. {"model": "my_module.models.MyModel"} in which case they will be automatically imported correctly.
  python-BaseException
  
  ```
  
  </p>
  </details>
  
  
  ## Related issues or possible duplicates
  
  - None
  
  
  ## Environment
  
  <!-- Provide the name of operating system below (e.g. OS X, Linux) -->
  OS: Windows 10
  
  <!-- Provide the Python version you were using (e.g. 3.7.1) -->
  Python version: 3.9.5
  allennlp 2.4.0
  
  