ci: Swap to release-please for releases over semantic-release

[codyfinegan]

Description

Fix for #401 - swapping to release-please over semantic release so releases can be held back and deployed in batches.

Testing Instructions

1. Review the github actions changes

Checklist

• Does what the author says it will do
• Testing instructions are provided
• Commit messages make sense and follow the conventional commit standard
• No identified security issues
• No identified maintenance issues
• Any third-party libraries/dependencies use the MIT or Apache 2.0 license
• Changes made are backwards compatible and will not break existing setups
• Changes to scripts in the bin/ directory run correctly on both MacOS and WSL
• Changes to containers can be built locally sucessfully (e.g. via tbuild container && tup container)
• Containers/images are compatible with both AMD64 (Windows) and ARM64 (MacOS)
• Changes made to config.php are compatible with our oldest supported Totara version, our newest Totara version, and Moodle

[codyfinegan]

CI build failures of PHP images are out of date & not covered by this ticket - will raise a independent PR (it's because things have shifted in debian.org)

#415

[Nathanael-from-Security]

Comfortable with the change, noting we should review who can create tags (aka trigger builds) in future.

Comfortable with the scoped perms! Change looks good.