Add lenient_issubclass and lenient_isinstance to DEPRECATED_MOVED_IN_V2

[Kludex]

This PR moves lenient_is* functions from "removed" to "deprecated" on the migration module.

Packages like FastAPI depends on those methods (actually only the lenient_issubclass), see:

❯ grep -r 'lenient_'                          
./fastapi/dependencies/utils.py:from pydantic.utils import lenient_issubclass
./fastapi/dependencies/utils.py:        and not lenient_issubclass(field.type_, BaseModel)
./fastapi/dependencies/utils.py:        and not lenient_issubclass(field.type_, sequence_types + (dict,))
./fastapi/dependencies/utils.py:    if (field.shape in sequence_shapes) and not lenient_issubclass(
./fastapi/dependencies/utils.py:    if lenient_issubclass(field.type_, sequence_types):
./fastapi/dependencies/utils.py:    if lenient_issubclass(type_annotation, Request):
./fastapi/dependencies/utils.py:    elif lenient_issubclass(type_annotation, WebSocket):
./fastapi/dependencies/utils.py:    elif lenient_issubclass(type_annotation, HTTPConnection):
./fastapi/dependencies/utils.py:    elif lenient_issubclass(type_annotation, Response):
./fastapi/dependencies/utils.py:    elif lenient_issubclass(type_annotation, BackgroundTasks):
./fastapi/dependencies/utils.py:    elif lenient_issubclass(type_annotation, SecurityScopes):
./fastapi/dependencies/utils.py:    if lenient_issubclass(
./fastapi/dependencies/utils.py:            if lenient_issubclass(field.type_, UploadFile):
./fastapi/dependencies/utils.py:                and lenient_issubclass(field.type_, bytes)
./fastapi/dependencies/utils.py:                and lenient_issubclass(field.type_, bytes)
./fastapi/openapi/utils.py:from pydantic.utils import lenient_issubclass
./fastapi/openapi/utils.py:                if lenient_issubclass(current_response_class, JSONResponse):
./fastapi/utils.py:from pydantic.utils import lenient_issubclass
./fastapi/utils.py:    if lenient_issubclass(original_type, BaseModel):
./fastapi/routing.py:from pydantic.utils import lenient_issubclass
./fastapi/routing.py:            if lenient_issubclass(return_annotation, Response):

Questions

• Should I move lenient_isinstance to the deprecated subpackge?

[samuelcolvin]

Also, we should probably so a few more:

(From searching sourcegraph for context:global from\ pydantic\.utils\ import\ (?:(\w+),? *)+)

[samuelcolvin]

Can we change this to import from pydantic.v1.utils, then remove them from pydantic._internal._utils?