class_docstr: This entity may change or be removed in a future release without warning.
  SQLAlchemy compliant backend store for tracking meta data for MLflow entities. MLflow
  supports the database dialects ``mysql``, ``mssql``, ``sqlite``, and ``postgresql``.
  As specified in the
  `SQLAlchemy docs <https://docs.sqlalchemy.org/en/latest/core/engines.html#database-urls>`_ ,
  the database URI is expected in the format
  ``<dialect>+<driver>://<username>:<password>@<host>:<port>/<database>``. If you do not
  specify a driver, SQLAlchemy uses a dialect's default driver.
  
  This store interacts with SQL store using SQLAlchemy abstractions defined for MLflow entities.
  :py:class:`mlflow.store.model_registry.models.RegisteredModel` and
  :py:class:`mlflow.store.model_registry.models.ModelVersion`
docstr: Delete a tag associated with the model version.
  
  :param name: Registered model name.
  :param version: Registered model version.
  :param key: Tag key.
  :return: None
docstr_tok: ["Delete","a","tag","associated","with","the","model","version",".",":","param","name",":","Registered","model","name",".",":","param","version",":","Registered","model","version",".",":","param","key",":","Tag","key",".",":","return",":","None"]
code: def delete_model_version_tag(self, name, version, key):
      """
      Delete a tag associated with the model version.
  
      :param name: Registered model name.
      :param version: Registered model version.
      :param key: Tag key.
      :return: None
      """
      _validate_model_name(name)
      _validate_model_version(version)
      _validate_tag_name(key)
      with self.ManagedSessionMaker() as session:
          # check if model version exists
          self._get_sql_model_version(session, name, version)
          existing_tag = self._get_model_version_tag(
              session, name, version, key
          )
          if existing_tag is not None:
              session.delete(existing_tag)
  
imports: import logging
  import urllib
  import sqlalchemy
  from sqlalchemy.future import select
  import mlflow.store.db.utils
  from mlflow.entities.model_registry.model_version_stages import ALL_STAGES, DEFAULT_STAGES_FOR_GET_LATEST_VERSIONS, STAGE_ARCHIVED, STAGE_DELETED_INTERNAL, get_canonical_stage
  from mlflow.exceptions import MlflowException
  from mlflow.protos.databricks_pb2 import INVALID_PARAMETER_VALUE, INVALID_STATE, RESOURCE_ALREADY_EXISTS, RESOURCE_DOES_NOT_EXIST
  from mlflow.store.artifact.utils.models import _parse_model_uri
  from mlflow.store.entities.paged_list import PagedList
  from mlflow.store.model_registry import SEARCH_MODEL_VERSION_MAX_RESULTS_DEFAULT, SEARCH_MODEL_VERSION_MAX_RESULTS_THRESHOLD, SEARCH_REGISTERED_MODEL_MAX_RESULTS_DEFAULT, SEARCH_REGISTERED_MODEL_MAX_RESULTS_THRESHOLD
  from mlflow.store.model_registry.abstract_store import AbstractStore
  from mlflow.store.model_registry.dbmodels.models import SqlModelVersion, SqlModelVersionTag, SqlRegisteredModel, SqlRegisteredModelAlias, SqlRegisteredModelTag
  from mlflow.utils.search_utils import SearchModelUtils, SearchModelVersionUtils, SearchUtils
  from mlflow.utils.time import get_current_time_millis
  from mlflow.utils.uri import extract_db_type_from_uri
  from mlflow.utils.validation import _validate_model_alias_name, _validate_model_name, _validate_model_version, _validate_model_version_tag, _validate_registered_model_tag, _validate_tag_name
label_desc: Use image node_id 36 for calling the SqlAlchemyStore obj's underlying member method code with example usage: obj.delete_model_version_tag(name, version, key) without return types