PEP517 compatibility

[CKannas]

We recently encountered an issue installing CGRTools as it isn't PEP517 compatible.

Since the latest PIP update v25.3 PEP517 installation is enforced which results in failure to compile CGRTools and install it.
For your reference check: pypa/pip#6334

[asiomchen]

Hi @CKannas , I recently encountered the same issue (on top of the issue with the recent Cython version)

So I created my fork - cgrtools-plus - drop-in replacement for cgrtools - PEP517 complient, with fixed Cython and prebuilt wheels for most systems

https://github.com/asiomchen/CGRtools