node12 github actions are deprecated - will stop working mid 2023

[GuySartorelli]

https://github.com/silverstripe/silverstripe-installer/actions/runs/3220762331
Github actions is throwing some warnings at us:

Node.js 12 actions are deprecated. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/. Please update the following actions to use Node.js 16: actions/checkout, actions/checkout

It says it'll stop working in "Summer 2023" which means june-ish

Acceptance criteria

• any action currently using node12 is updated to use the latest runner.

Notes

• We should still be able to use older version of node for our builds. Just not for the actual runner.
• Note should be able to update the central github actions without having to update every single builds.

PRs

• DEP Use deps that use node16+ #66
• DEP Use deps that use node16+ gha-update-js#11
• DEP Use deps that use node16+ gha-generate-matrix#56

[emteknetnz]

Have merged and released all prs

[GuySartorelli]

Reopened to verify that the deprecation notices are gone

[GuySartorelli]

Deprecation notices aren't being emitted anymore