Fix LSP warnings and navigation on JS-related code

[Fryuni]

Changes

Mark files that rely on syscall/js with build tags targeting JS and WASM, the same as the syscall/js package itself.

GoPls shows this warning when working on the project locally so things get annoying with tools that aim to keep the project always green like preventing commits in a broken state without extra confirmation jumping to definitions to explore the codebase since it consider those references broken.

Which then makes GoPls consider all the imports that are JS-only as exporting nothing:

Additionally, go.mod had a dependency marked as indirect but it is actually used directly by our tests. So just running go mod tidy causes the changes committed there.

[changeset-bot]

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Latest commit: be823c0

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