chore(deps): update pnpm to v8.15.7

[renovate]

This PR contains the following updates:

Package	Type	Update	Change	OpenSSF
pnpm (source)	packageManager	patch	8.15.6 -> 8.15.7

---

Release Notes

pnpm/pnpm (pnpm)

v8.15.7

Compare Source

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate. View repository job log here.

[renovate]

⚠ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: pnpm-lock.yaml

Scope: all 14 projects
undefined
/tmp/renovate/repos/github/stainless-api/release-please/test/fixtures/plugins/node-workspace/node1:
 ERR_PNPM_FETCH_404  GET https://registry.npmjs.org/anotherExternal: Not Found - 404

This error happened while installing a direct dependency of /tmp/renovate/repos/github/stainless-api/release-please/test/fixtures/plugins/node-workspace/node1

anotherExternal is not in the npm registry, or you have no permission to fetch it.

No authorization header was set for the request.
undefined
undefined