fix: reset printToPDF queue after a rejection
The module-scoped `pendingPromise` in `webContents.printToPDF` was chained
with `.then(onFulfilled)` and never cleared. Once a call rejected (e.g.
an out-of-range `pageRanges` like `"999"`), subsequent calls chained onto
the rejected promise and short-circuited without ever invoking
`_printToPDF` — so every following call re-surfaced the original error.
Replace the shared variable with a per-`WebContents` `WeakMap` queue that
swallows prior rejections before chaining and clears its entry once the
tail drains.
Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>
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