See Changelog.

• Change schema and schema_model to handle dataclasses by using their __pydantic_model__ feature, #792 by @aviramha
• Added option for root_validator to be skipped if values validation fails using keyword skip_on_failure=True, #1049 by @aviramha
• Allow Config.schema_extra to be a callable so that the generated schema can be post-processed, #1054 by @selimb
• Update mypy to version 0.750, #1057 by @dmontagu
• Trick Cython into allowing str subclassing, #1061 by @skewty
• Prevent type attributes being added to schema unless the attribute __schema_attributes__ is True, #1064 by @samuelcolvin
• Change BaseModel.parse_file to use Config.json_loads, #1067 by @kierandarcy
• Fix for optional Json fields, #1073 by @volker48
• Change the default number of threads used when compiling with cython to one, allow override via the CYTHON_NTHREADS environment variable, #1074 by @samuelcolvin
• Run FastAPI tests during Pydantic's CI tests, #1075 by @tiangolo
• My mypy strictness constraints, and associated tweaks to type annotations, #1077 by @samuelcolvin
• Add __eq__ to SecretStr and SecretBytes to allow "value equals", #1079 by @sbv-trueenergy
• Fix schema generation for nested None case, #1088 by @lutostag
• Consistent checks for sequence like objects, #1090 by @samuelcolvin
• Fix Config inheritance on BaseSettings when used with env_prefix, #1091 by @samuelcolvin
• Fix for __modify_schema__ when it conflicted with field_class_to_schema*, #1102 by @samuelcolvin
• docs: Fix explanation of case sensitive environment variable names when populating BaseSettings subclass attributes, #1105 by @tribals
• Rename django-rest-framework benchmark in documentation, #1119 by @frankie567