Python evolves and certain things from the development setup simply
stopped working. This was also mentioned few times by the people
struggling to start development version of Keystone locally. In addition
to that certain steps are not being ordered properly what confuses
people not knowing technical details.
This change modifies the doc by explicitly using python 3.11, reodrering
steps as required and adding clarifications on the database setup.
Closes-Bug: 2074045
Change-Id: I2eefc91594bac516e076cc60ae1fcdd7e704eab4