* add new python versions to tox

* added codeql actions

* drop as we dont use travis

* added tidelift alignment action

* Adding two tests, for Connection.collect and Transport.close.

* revert 3.6 removal

* update classifier

* reorganize CI process and aded new python versions

* remove python 3.10 from CI actions for now

Co-authored-by: VinayGValsaraj <vinaygvalsaraj@gmail.com>

* Pass long_description to setup()

* Remove unused import

* set cython language_level = 3
* Cythonize amqp.method_framing.Buffer
* Use directly chr() function
* Cythonize str_to_bytes() and bytes_to_str() in amqp/utils.py

The version 5.0 is currently an alpha version
but pypi classifiers tag this version as a production/stable version,
this is wrong, this version is a pre-alpha version.

The main issue is that by using pip or requirements file to install
py-amqp it will pull and install the pre-alpha version (5.0) instead of
the stable version 2.5.2.

Normally pip don't install non stable version except if user
explicitly specify to install a non stable version.

Example with oslo.messaging:

```
$ pip install oslo.messaging
```

The previous command will pull py-amqp 5.0