Jara-utils

* Remove `update.sh` script;
* Remove `flake8` and all the flake8 plugins;
* Add `ruff` and `black`
* Apply changes required by `ruff` and `black`
* Move `setup.cfg` to `pyproject.toml`
* Rename `exceptions.EnvironmentVariableNotFound` to `exceptions.EnvironmentVariableNotFoundError`
* Remove `update.sh` script
* Drop support for 3.9

* Updated docs, cleanup github actions;
* Moved ``pytest-sugar`` and ``pytest-deadfixtures`` to dev dependencies;
* Added ``ipdb`` and ``iptyon`` to dev dependencies;
* Added ``update.sh`` script, to update all the dependencies to last version;
* Updating pytz (2020.5 -> 2021.1)
* Installing types-pytz (2021.1.0)
* Updating flake8 (3.8.4 -> 3.9.2)
* Updating flake8-plugin-utils (1.3.1 -> 1.3.2)
* Updating flake8-annotations (2.5.0 -> 2.6.2)
* Updating flake8-comprehensions (3.3.1 -> 3.5.0)
* Updating flake8-multiline-containers (0.0.17 -> 0.0.18)
* Updating flake8-pytest-style (1.3.0 -> 1.5.0)
* Updating flake8-simplify (0.12.0 -> 0.14.1)
* Updating pytest (6.2.1 -> 6.2.4)
* Updating pytest-asyncio (0.14.0 -> 0.15.1)
* Updating pytest-cov (2.11.1 -> 2.12.1)

* Add support for Python 3.12;

* Drop support for Python 3.7 and add support for Python 3.8;
* Add ``aenumerate`` and ``async_grouper``;
* Add ``flake8-commas`` and ``flake8-eradicate``;

* Small updates for pypi;

~~~~~