Remove -<VERSION> suffix from name of checks in PRs

[romaricpascal]

What

Remove the -<VERSION> (the -22.04 of ubunu-22.04 or -latest of windows-latest) from the name of the various checks that run when a PR is raised, especially those that are required checks.

Why

Until we run checks against multiple versions of the same OS, the only relevant information to us is the OS. Having the version in the name gets in the way of changing the version we run against, like we recently had to when our tests had issues with ubuntu-latest and we had to downgrade to ubuntu-22.04. This required us to update the required checks in the repository's settings, which is extra admin that only listing the OS name would avoid.

Who needs to work on this

Developers

Who needs to review this

Developers

Done when

• Checks on the govuk-frontend repository only have the OS in their name
• Checks on the govuk-design-system repository only have the OS in their name
• Checks on the govuk-frontend-docs repository only have the OS in their name (if applicable)