node16 in GitHub Actions goes EOL on October 15

[GuySartorelli]

https://github.blog/changelog/2024-09-25-end-of-life-for-actions-node16/

From the 15th of October, we will no longer include Node16 in the Actions runner and customers will no longer be able to use Node16 Actions or operating systems that do not support Node20.

We've been ignoring those deprecations for a while, but it's time we finally do something about it. Should just mean bumping the version of various actions we're using in our workflows.

PRs

• MNT Update GHA dependencies developer-docs#595
• MNT Update GHA dependencies gha-action-ci#18
• MNT Update GHA dependencies gha-auto-tag#25
• MNT Update GHA dependencies gha-ci#156
• MNT Update GHA dependencies gha-generate-matrix#110
• MNT Update GHA dependencies gha-merge-up#45
• MNT Update GHA dependencies gha-update-js#33
• MNT Update GHA dependencies module-standardiser#72

[GuySartorelli]

Looked through the changelogs for the deps we need to upgrade. Only one indicated breaking changes, and there's nothing in its migration guide that applies to us. So fingers crossed should be as simple as updating the hash.