Remove cut task

[starbelly]

As part of V7 the cut command is removed in this commit. We can bring it back later or perhaps better it becomes its own plugin.

• remove rebar3_hex_cut.erl
• remove rebar3_hex_cut from rebar3_hex:init/1
• remove reference to cut to in rebar3_hex_publish

[tsloughter]

Uh, what? Why? Is this functionality provided by another command now? If not, please add this back.

[paulo-ferraz-oliveira]

Ref: https://github.com/erlef/rebar3_hex/issues/221#issuecomment-835420930