ci: update prepare release pull request title

[herrardo]

Pull request template

Change the title of the PR created when the prepare-release action is created

Motivation and context

The title of the PRis used for the stash commit.

When the PR is merged the workflow to create the alpha SHOULD NOT BE FIRED

For that we can do 2 things:

• Stop the workflow manually to no create the alpha when that PR is merged, which is dangerous because we can forget
• Change the title of the PR to chore(release): prepare stable release because the alpha release checks that title and stops if the commit contains chore(release)

• Dependencies. If any, specify:
• Open issue. If applicable, link:

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that causes existing functionality to not work as expected)
• Change requires a documentation update

What is the destination branch of this PR?

• Main
• Other. Specify:

How has this been tested?

Tests performed according to testing guidelines:

Checklist:

• My code follows the style guidelines of this project.
• I have performed a self-review on my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.