lake: redundant missing import errors

Here is an example failing build of Mathport due to a moved upstream file:

$ lake build
✖ [63/1717] Running Mathlib.Init.ZeroOne
error: no such file or directory (error code: 2)
  file: ././.lake/packages/mathlib/././Mathlib/Init/ZeroOne.lean
✖ [64/1717] Running Mathport.Binary.Number
error: ././././Mathport/Binary/Number.lean: bad import 'Mathlib.Init.ZeroOne'
✖ [65/1717] Running Mathport.Binary.Heterogenize
error: ././././Mathport/Binary/Heterogenize.lean: bad import 'Mathport.Binary.Number'
✖ [66/1717] Running Mathport.Binary.TranslateExpr
error: ././././Mathport/Binary/TranslateExpr.lean: bad import 'Mathport.Binary.Number'
error: ././././Mathport/Binary/TranslateExpr.lean: bad import 'Mathport.Binary.Heterogenize'
✖ [67/1717] Running Mathport.Binary.Apply
error: ././././Mathport/Binary/Apply.lean: bad import 'Mathport.Binary.TranslateExpr'
✖ [68/1717] Running Mathport.Binary
error: ././././Mathport/Binary.lean: bad import 'Mathport.Binary.Apply'
✖ [1641/1717] Running Mathport
error: ././././Mathport.lean: bad import 'Mathport.Binary'
✖ [1642/1717] Running MathportApp
error: ././././MathportApp.lean: bad import 'Mathport'
✖ [1644/1717] Running mathport
error: ././././MathportApp.lean: bad import 'Mathport'

The first error is correct, but all subsequent errors are incorrect / misleading. Essentially, if a file imports a nonexistent file, then that file will itself be considered nonexistent by its dependencies, possibly leading to hundreds of cascading failures, within which the original error might be hard to spot.

Tested on Lake version 5.0.0-702c31b (Lean version 4.10.0-rc2).

Reproduce the cascade with lake build using the Mathport example, starting with the missing Mathlib.Init.ZeroOne import and the subsequent Mathport.Binary failures. Inspect Lake's import and dependency error handling; done means the original missing-file error remains visible without misleading cascading missing-import errors.