hatch: Actually include sourcefiles in wheel

After I published v0.1.7, I noticed the source files were missing from the wheel.
This makes that version of the library impossible to use.

I have yanked v0.1.7 and will publish this commit as v0.1.8.
The only change is the fixed wheel.

This was caused by the transition from setuptools -> hatch
and it should not happen again.

Implement bulk remove via __isub__ operator

Reference in OrderedSet.remove docs as a way
to avoid quadratic behavior.

Improve documentation

Enable `pydocstyle` lints

More efficient pickling

Because pickling preserves object identity,
the behavior was still correct before,
it was just less efficient.

The new version is fully backwards compatible,
and is still able to deserialize data from v0.1.4.
There is a test to make sure this is true.

Fixes #5

Add OrderedSet.dedup method

An iterator comabinator that removes duplicate elements while preserving ordering.
Because it is implemented as a generator, it does not need to wait
for the entire input before yielding values.

Add OrderedSet.dedup_async which does the same thing for AsyncIterator

Support pydantic validation & serialization

Pydantic is an optional dependency.
The library still works fine without it.

- Change `__repr__` to use list literal notation:
    - Now is `OrderedSet([1, 2, 3])` instead of `OrderedSet((1, 2, 3))`
    - The __str__ representation is still `{1, 2, 3}`
- Use PEP 639 license metadata
- Improve README, fixing bug and documenting pydantic support

Drop cython build dependency

Not used

Use 'techcable' as a namespace, not a package

Avoids conflicts with my other libraries that use 'techcable'.
Namespace packages are described in PEP 420.

Initial release