[doc] Update book sections about cubes being Python packages Related to #1300146006.

[doc] Start filling changes/3.24.rst with recent changes

[doc] Drop commented mention of "live-server" command Follow-up for d83676aaea21.

[pyramid] Drop guard of old cubicweb version

[pkg] Declare extras (optional) dependencies This is primary to extract "pyramid" dependencies out of install_requires as they are actually optional. Along the way, resurrect all things in __pkginfo__.__recommends__ which were not used at all and convert them into extra_requires. It appears that __depends__ and __recommends__ in __pkginfo__.py are not useful so drop them and inline dependencies as install_requires/extra_requires in setup function call. For pyramid tests to continue working, add respective dependencies to test-misc.txt requirements file.

[tox] Exclude all files in symlinked directories from check-manifest call

[tox] Get rid of "touch test-results.xml" for flake8 and check-manifest environments CI server does not rely on this anymore.

[debian] cubicweb-pyramid conflicts and replaces pyramid-cubicweb Related to #14023058.

Merge cubicweb-pyramid cube Only keep the CWSession schema definition and the ctl command, now in cubicweb/pyramid/pyramidctl.py Related to #14023058.

[ccplugin] flake8