When some of our test mocks intentionally respond with a 500, that response takes several seconds because the [client's `fetch` function](https://github.com/vercel/vercel/blob/7e8fbd20e01135513ad28936155b078650732d37/packages/cli/src/util/client.ts#L173-L174) automatically retries the request. 

But since we're mocking these requests we should just automatically fail.

For those of us who use a debugger, the test suit exiting early is frustrating. You can get around this by setting this value yourself or running with `--testTimeout` in the terminal but adding this behavior globally seems like a nice quality of life change.

I couldn't find a 100% guaranteed way to detect if node is in debug mode but the rough consensus was detecting  `debugPort` covered the largest number of cases.

I audited all the uses of `vi.setConfig({ testTimeout });` in `packages/cli` and only found one that looked like it could definitely be removed. The use case it covered was negated by #12354.

The others mostly came from 413706d or had a comment explaining their need.

For those of us who use a debugger, the test suit exiting early is frustrating. You can get around this by setting this value yourself or running with `--testTimeout` in the terminal but adding this behavior globally seems like a nice quality of life change.

I couldn't find a 100% guaranteed way to detect if node is in debug mode but the rough consensus was detecting  `debugPort` covered the largest number of cases.

I audited all the uses of `vi.setConfig({ testTimeout });` in `packages/cli` and only found one that looked like it could definitely be removed. The use case it covered was negated by vercel/vercel#12354.

The others mostly came from vercel/vercel@fa07756 or had a comment explaining their need.