Pin GitHub actions

[edgarrmondragon]

[henryiii]

Okay if you want to, but I'm personally not a fan of pinning GHA. The reason is that the underlying images are fluid, and change regularly. Pinning can actually break actions, because the underlying image updates something (powershell, or the artifact system being two recent examples), causing the pinned version to fail when a looser version would actually have passed due to fixes being applied. I only like pinning less well maintained actions.