fix(turbopack): reduce severity of resolve issues during analysis (#69626)
### What?
During analysis, we try to expand `require.resolve` and
`require.context` to get additional information as early as possible.
This can lead to `ResolvingIssue` being emitted, which mark the build as
failed.
In general this is fine, but due to the way `link` works current we
don't have information on whether the call causing the `ResolvingIssue`
is inside a `try {} catch {}` causing the build to fail unnecessarily.
This PR reduces the severity to always be `IssueSeverity::Warning` to
remedy the problem.
We will still emit a `ResolvingIssue` with `IssueSeverity::Error` later
on inside the references if the call is not inside a `try {} catch {}`.
Closes PACK-2952
Fixes #64423