fix: JSON modules disable named exports

[JLHwung]

Description

Updated the import-assertions js formatter test, as the JSON modules spec disallows named exports. For example, export { foo2 } from "./foo.json" assert { type: "json" } is invalid.

Currently blocking babel/babel#14668. Babel plans to throw named JSON module imports/exports in the future, hence I update the test so the Babel update won't break our tests.

Checklist

• I’ve added tests to confirm my change works.
• (If changing the API or CLI) I’ve documented the changes I’ve made (in the docs/ directory).
• (If the change is user-facing) I’ve added my changes to changelog_unreleased/*/XXXX.md file following changelog_unreleased/TEMPLATE.md.
• I’ve read the contributing guidelines.

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[fisker]

Will it unblock babel PR if we test those in https://github.com/prettier/prettier/tree/main/tests/format/misc/errors?

[JLHwung]

@fisker Yes that could work, though eventually we have to revise the affected test cases. If you insist I can simply rename the test cases.

[fisker]

Not important.