Make sure all deprecations are properly removed

Description

Right now we've lost track of deprecated functions. See #111

import warnings
import functools

__version__ = "0.1.1"
def deprecate(*, start: str, removed: str):
    if __version__ >= removed:
        raise RuntimeError(f"After incrementing version {__version__} this function has to be removed")
    else:
        def wrapper(fn):
            @functools.wraps(fn)
            def wrapped_fn(*args, **kwargs):
                warnings.warn(f"This function is deprecated in version {start} and "
                              f"will be removed at version {removed}. Current version is {__version__}.", DeprecationWarning)
                return fn(*args, **kwargs)
            return wrapped_fn
        return wrapper

gives

@deprecate(start="0.0.1", removed="1.1.1")
def add(x, y):
    return x + y
add(1, 2)

/var/folders/rx/rk9gm4ln35z802s3p81wfz8r0000gp/T/ipykernel_10024/2831940282.py:9: DeprecationWarning: This function is deprecated in version 0.0.1 and will be removed at version 1.1.1. Current version is 0.1.1.
  warnings.warn(f"This function is deprecated in version {start} and "

And during increment version PR

@deprecate(start="0.0.1", removed="0.1.1")
def add(x, y):
    return x + y

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
Cell In [19], line 1
----> 1 @deprecate(start="0.0.1", removed="0.1.1")
      2 def add(x, y):
      3     return x + y

Cell In [16], line 4, in deprecate(start, removed)
      2 def deprecate(*, start: str, removed: str):
      3     if __version__ >= removed:
----> 4         raise RuntimeError(f"After incrementing version {__version__} this function has to be removed")
      5     else:
      6         def wrapper(fn):

RuntimeError: After incrementing version 0.1.1 this function has to be removed

For flexibility we can build similar thing on top of
https://borda.github.io/pyDeprecate/

Start by reviewing the deprecation discussion in #111 and the proposed Python decorator behavior shown in this issue. Compare the desired version-checking workflow with pyDeprecate. Done should mean deprecated functions are tracked and removed appropriately during version increments, but the issue does not identify files or tests.