### Description
* The `consistent-deps.sh` was fixed to take into account the ingest
dependencies, causing some errors to show up. New constriants were added
to make that script pass.
* Update all requirements without constraint on pydantic, allowing the
latest version to be pulled in.
* `pikepdf` is causing a conflict but there's a fix on their `main`
branch, just need for the next release to be published. Opened up a
question here to see if we can get that out any sooner: [Do releases
happen on a
schedule?](https://github.com/pikepdf/pikepdf/discussions/574). For now
added `lxml<5` to the constraints.
A couple optimizations:
* `constraints.in` renamed to `constraints.txt` since the whole point is
all dependencies are already pinned and the file never gets compiled
* `constraints.txt` moved to a `requirements/deps` directory as this
never gets compiled by `pip-compile`
* Other dependency files updated to reference the new location of
`base.in` and `constraints.txt`
* make file updated since it was originally written to avoid the
`base.in` and `constraints.in` file
### Description
Given all the shell files that now exist in the repo, would be nice to
have linting/formatting around them (in addition to the existing
shellcheck which doesn't do anything to format the shell code). This PR
introduces `shfmt` to both check for changes and apply formatting when
the associated make targets are called.
Addresses #631.
* Uses constraints to keep dependency versions more consistent.
* Moves all dependencies to .in files which are then ingested by setup.py.
* Adds script to check consistency of all extras.
* Adds consistency check to CI.
I should note that while it shouldn't be possible to cause a conflict between base.txt and any of the extras (because base.txt constrains all the extras) it is possible to get a conflict between two of the extras files. There are ways of trying to avoid that (like constraining each file by all the files that have already been processed before it in the order given in the make pip-compile target) but the ones I could think of seemed a little overwrought, and come with problems of their own. If a conflict arises, it should be flagged by CI or locally with make check-deps. When/if that happens, you can resolve the conflict by adding appropriate global constraints in requirements/constraints.txt.
Also note that if fileA.in is constrained by fileB.txt, then fileB.in should be compiled before fileA.in in the make pip-compile target. Otherwise fileA.in will be compiled with the old version of fileB.txt which can cause conflicts or keep dependencies from being updated properly.
