Replace isort, flake8, pycln and pyupgrade by ruff. [Ruff](https://github.com/charliermarsh/ruff) is getting popular lately, and I really like the idea of having a single tool for Python lining instead of N which currently exist. Also written in Rust which is a good use case for this.

 It's supposed to have equivalent functionality, to the ones we are using. The fact that major projects are adopting it is a good sign (see list in their readme).  There are also a few extra options in their readme that look interesting and that we could enable (without having to install yet another plugin)

We won't gain much speed-wise: previously isort, flake8 (which itself is an abstraction over pycodestyle and pyflakes), pycln and pyupgrade  on all files was around 1s, and now it's 20ms. But with mypy taking 10s, it makes mostly no difference.
Still it makes the overall linting configuration easier to maintain.


If we go forward with this, I imagine a changelog is not needed? 

package:
  name: gmpy2
  version: 2.1.4
  top-level:
    - gmpy2
source:
  url: https://files.pythonhosted.org/packages/12/8c/2ec8c83138cd56a2b8e7ccb87095f9e6402c64aa26a2ff3dfddb232e8cc6/gmpy2-2.1.4.tar.gz
  sha256: 37a9959dae0d008fa750cbcdedd43518b7a1bdaa95a19f30effc6d045ad7adbd

requirements:
  host:
    - libmpc

build:
  cflags: |
    -I$(WASM_LIBRARY_DIR)/include
  ldflags: |
    -L$(WASM_LIBRARY_DIR)/lib
about:
  home: https://github.com/aleaxit/gmpy
  PyPI: https://pypi.org/project/gmpy2
  summary: gmpy2 interface to GMP/MPIR, MPFR, and MPC for Python 2.7 and 3.5+
  license: LGPL-3.0+

package:
  name: gmpy2
  version: 2.1.4
  top-level:
    - gmpy2
source:
  url: https://files.pythonhosted.org/packages/12/8c/2ec8c83138cd56a2b8e7ccb87095f9e6402c64aa26a2ff3dfddb232e8cc6/gmpy2-2.1.4.tar.gz
  sha256: 37a9959dae0d008fa750cbcdedd43518b7a1bdaa95a19f30effc6d045ad7adbd

requirements:
  host:
    - libmpc

build:
  cflags: |
    -I$(WASM_LIBRARY_DIR)/include
  ldflags: |
    -L$(WASM_LIBRARY_DIR)/lib
about:
  home: https://github.com/aleaxit/gmpy
  PyPI: https://pypi.org/project/gmpy2
  summary: gmpy2 interface to GMP/MPIR, MPFR, and MPC for Python 2.7 and 3.5+
  license: LGPL-3.0+
