Add a Hatchling plugin

[twm]

Fixes #93.

[adiroiban]

I did a very quick review.
I don't care too much about incremental or hatchling ... so this is a superficial review.

At the same time, other tha you Tom, I don't know if there are other maintainers for the incremental project.

So as long as you are happy with the PR. It can be merged.

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I see that this also updates the build system with locked / fully pinned dependencies.

I know that CI were failing in the past due to various deps missmatch.

At the same time, executing the tests using just the deps resolved by pip at test runtime should produce a testing environment that is closed to what newer users might experience.

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I am approving this, so that this PR can be merged.

I have also added back Twisted contributors, if someone else who cares more about incremetal will want to review it.

If in a few theres, there are no other reviews, I think that this can be merged.

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I guess that once a new version is released, incremental can use hatching for its build system.

Thanks

[twm]

Thank you for the review @adiroiban! I'll try to release Incremental ASAP so you can use it in the next Twisted release.

I see that this also updates the build system with locked / fully pinned dependencies.

I know that CI were failing in the past due to various deps missmatch.

At the same time, executing the tests using just the deps resolved by pip at test runtime should produce a testing environment that is closed to what newer users might experience.

Agreed, I have somewhat mixed feelings about this. However the dep tree is large enough with both Twisted and Hatch in the mix that I'd prefer to lock.