Infra: The release process order of operations may be broken under Yarn 4

[daneah]

Expected behavior
The release goes off without a hitch

Actual behavior
Errors encountered during the release process

Steps to reproduce the issue

1. Visit the Actions log for the v14.0.0 release
2. Observe the error, having to do with Yarn expecting an immutable install but instead seeing that the @ithaka/pharos version will be updated for @ithaka/pharos-site

Screenshots or code

Run yarn --check-cache --immutable
➤ YN0000: · Yarn 4.1.0
➤ YN0000: ┌ Resolution step
Resolution step
➤ YN0000: └ Completed in 0s 66[8](https://github.com/ithaka/pharos/actions/runs/8194158743/job/22409560036#step:6:9)ms
➤ YN0000: ┌ Post-resolution validation
Post-resolution validation
➤ YN0028: -    "@ithaka/pharos": "npm:^13.3.0"
➤ YN0028: +    "@ithaka/pharos": "npm:^14.0.0"
➤ YN0028: -"@ithaka/pharos@npm:^13.3.0, @ithaka/pharos@workspace:packages/pharos":
➤ YN0028: +"@ithaka/pharos@npm:^14.0.0, @ithaka/pharos@workspace:packages/pharos":
➤ YN0028: The lockfile would have been modified by this install, which is explicitly forbidden.
➤ YN0000: └ Completed
➤ YN0000: · Failed with errors in 0s 833ms
Error: Process completed with exit code 1.

Additional information

This may be due to how Yarn 4 handles workspace dependencies, as this release was the first one done using Yarn 4 instead of Yarn 1. Because the release process includes bumping the version of the @ithaka/pharos package, and because the @ithaka/pharos-site package depends on it as a workspace, Yarn wants to bump it as well, and because this all happens prior to running yarn ... --immutable, the installation fails because this change is "pending."

[daneah]

One possible fix entails running yarn install (without --immutable) after running yarn release, as part of the steps in the release workflow, and pushing the result to the branch that's created. This will ensure that what gets merged into main from the pull request already has the "undesired" changes that happen when actually trying to generate the release. It also makes sure that @ithaka/pharos-site is always using the latest release of @ithaka/pharos.

We recently ran into issues with that, too, though, because the site hadn't been updated to accommodate breaking major changes. So a different solution would be to make sure the workspaces aren't actually coupled, such that @ithaka/pharos-site can statically reference some version of @ithaka/pharos and doesn't get updated at all as part of this flow. This is the "safest," but also means we could be inclined to get outdated.

[daneah]

Consider investigating #668 in tandem.

[daneah]

This issue did not occur in a recent release—will need to better understand what triggers Yarn to update the workspace dependencies during this flow.