Switch to 0.x as default branch name

[MasterOdin]

Currently, phinx uses master as the default branch name. To align with how other cakephp projects work where the default branch is the current version number, we want to switch this repo to use 0.x.

[MasterOdin]

Currently, we have both master and 0.x branches existing in the repo, and they differ with two PRs:

• master has Fix setting persistent option for PDO connection #2092
• 0.x has Add php 8.2 to github actions and update versions #2096 + e9804ca

The two options as I see it would be:

• Just change the default branch from master to 0.x and then rebase 11ec6ee on top of 0.x
• Rebase Add php 8.2 to github actions and update versions #2096 + e9804ca from 0.x onto master, delete 0.x, and then rename the default branch

My vote would be on the second option as it will also update all existing PRs to also point at the new 0.x if they were pointing at master, and that anyone who looks at the repo will get a nice little GH popup that gives instructions on what someone needs to run in their local console to point to the new branch name.

pinging @dereuromark and @othercorey on this as some discussion of this has happened on slack and within above PRs.

[othercorey]

The master branch was renamed to 0.x.