Packaging for release v18.1.0

[gonzaloriestra]

What this PR does

Release new version including:

• Support Rails 7 #1354
• Fix webhooks handling in Ruby 3 #1342
• Update to Ruby 3 and drop support to Ruby 2.5 #1359

Checklist

Before submitting the PR, please consider if any of the following are needed:

• Update CHANGELOG.md if the changes would impact users
• Update README.md, if appropriate.
• Update any relevant pages in /docs, if necessary
• For security fixes, the Disclosure Policy must be followed.