Build tools: remove pyproject.toml

[hmaarrfk]

fixes: #3576
fixes: #3685

cc: @jni @stefanv

Description

[Tell us about your new feature, improvement, or fix! If relevant, please supplement the PR with images.]

Checklist

[It's fine to submit PRs which are a work in progress! But before they are merged, all PRs should provide:]

• Clean style in the spirit of PEP8
• Docstrings for all functions
• Gallery example in ./doc/examples (new features only)
• Benchmark in ./benchmarks, if your changes aren't covered by an
  existing benchmark
• Unit tests

[For detailed information on these and other aspects see scikit-image contribution guidelines]

References

[If this is a bug-fix or enhancement, it closes issue # ]
[If this is a new feature, it implements the following paper: ]

For reviewers

(Don't remove the checklist below.)

• Check that the PR title is short, concise, and will make sense 1 year
  later.
• Check that new functions are imported in corresponding __init__.py.
• Check that new features, API changes, and deprecations are mentioned in
  doc/release/release_dev.rst.
• Consider backporting the PR with @meeseeksdev backport to v0.14.x

[hmaarrfk]

@soupault thanks for that tiny fix.

[hmaarrfk]

Even more reasons to get ride of this.

ERROR: Error installing 'file:///home/mark2/git/scikit-image': editable mode is not supported for pyproject.toml-style projects. pip is processing this project as pyproject.toml-style because it has a pyproject.toml file. Since the project has a setup.py and the pyproject.toml has no "build-backend" key for the "build_system" value, you may pass --no-use-pep517 to opt out of pyproject.toml-style processing. See PEP 517 for details on pyproject.toml-style projects.

[hmaarrfk]

@meeseeksdev backport to v0.14.x

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

$ git checkout v0.14.x
$ git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

$ git cherry-pick -m1 89b770213692734a228264c1cb00875c68f56b91

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

$ git commit -am 'Backport PR #3688: Build tools: remove pyproject.toml'

4. Push to a named branch :

git push YOURFORK v0.14.x:auto-backport-of-pr-3688-on-v0.14.x

5. Create a PR against branch v0.14.x, I would have named this PR:

"Backport PR #3688 on branch v0.14.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to suggest an improvement.