chore: Use setup-node action to cache yarn deps in github actions workflow.

[cullylarson]

setup-node will cache packages on its own. C.f.:

• https://github.com/actions/setup-node#caching-global-packages-data
• https://github.com/actions/setup-node/blob/main/docs/advanced-usage.md#caching-packages-data

This PR removes our custom caching and replaces it with setup-node's own cache.

I tested this on Clerestory. "Control" is the old workflow, "Update" is the new workflow.

	Control 1	Control 2	Update 1	Update 2
	103	57	79	79
	66	76	80	110
	68	61	78	90
	71	68	85	77
	68	73	87	108
Average	75.2	67	81.8	92.8

It looks like it's a little slower. Maybe not a beneficial change? It could be that node-setup is doing some extra things that we aren't. But if that doesn't benefit us in terms of runtime, it's probably not worth it. Some pros and cons:

Pros

1. node-setup will presumably continue to improve. It could also just be GA's inconsistency in runtimes.
2. It's simpler.

Cons

1. Potentially slower, but it's hard to tell for sure.
2. It isn't as explicit as the old solution. I could see someone implementing the old solution again because they think caching is missing. That might not make it past PR review to get into Bison again, but someone who uses it to build a project could easily think that.

Checklist

• [x] Generating a new app works

[cball]

👍 simpler is better here and I agree leaning on something provided by the platform is a good call.