ci: resolve Vercel deployments from the Vercel API (#4313)

* ci: resolve Vercel deployments from the Vercel API

Replace vercel/wait-for-deployment-action, which requires a GitHub
Deployment object that SUGP drops when the shared GitHub App
installation is rate limited, with a local action that polls the Vercel
API by project, commit, branch, and target environment.

The action also derives the changeset-release base-commit rule and the
Vercel environment, replacing the duplicated wait steps and branch
expressions in tests.yml, benchmarks.yml, and event-log-race-repro.yml.

Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>

* ci: extract the resolver's timeout error

Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>

* ci: resolve skipped builds and redeploys

Vercel records a skipped build as a CANCELED deployment. Resolve it to
the branch's previous ready deployment instead of waiting out the
timeout, and accept redeploys of a Git deployment.

Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>

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Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>