remove APIs that are marked deprecated since v0.6 and v0.7?

[wyli]

Is your feature request related to a problem? Please describe.
some APIs such as

MONAI/monai/networks/blocks/convolutions.py

Line 101 in 535c6f1

name="dimensions", new_name="spatial_dims", since="0.6", msg_suffix="Please use `spatial_dims` instead."

MONAI/monai/transforms/post/dictionary.py

Lines 137 to 154 in 535c6f1

	@deprecated_arg(name="n_classes", new_name="num_classes", since="0.6", msg_suffix="please use `to_onehot` instead.")
	@deprecated_arg("num_classes", since="0.7", msg_suffix="please use `to_onehot` instead.")
	@deprecated_arg("logit_thresh", since="0.7", msg_suffix="please use `threshold` instead.")
	@deprecated_arg(
	name="threshold_values", new_name="threshold", since="0.7", msg_suffix="please use `threshold` instead."
	)
	def __init__(
	self,
	keys: KeysCollection,
	argmax: Union[Sequence[bool], bool] = False,
	to_onehot: Union[Sequence[Optional[int]], Optional[int]] = None,
	threshold: Union[Sequence[Optional[float]], Optional[float]] = None,
	rounding: Union[Sequence[Optional[str]], Optional[str]] = None,
	allow_missing_keys: bool = False,
	n_classes: Optional[Union[Sequence[int], int]] = None, # deprecated
	num_classes: Optional[Union[Sequence[int], int]] = None, # deprecated
	logit_thresh: Union[Sequence[float], float] = 0.5, # deprecated
	threshold_values: Union[Sequence[bool], bool] = False, # deprecated

are deprecated since version 0.6 and 0.7, they (and their corresonding tests) could be removed.

[Nic-Ma]

Thanks for raising the request.
Let me try to make a PR for it.

Thanks.