Bump pnpm to 8.15.8

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
pnpm (source)	8.15.7 -> 8.15.8

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Release Notes

pnpm/pnpm (pnpm)

### [`v8.15.8`](https://togithub.com/pnpm/pnpm/compare/v8.15.7...v8.15.8) [Compare Source](https://togithub.com/pnpm/pnpm/compare/v8.15.7...v8.15.8)

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