Bump libsodium-wrappers from 0.7.13 to 0.7.15 (#427)

Bumps [libsodium-wrappers](https://github.com/jedisct1/libsodium.js) from 0.7.13 to 0.7.15.
- [Commits](jedisct1/libsodium.js@0.7.13...0.7.15)

---
updated-dependencies:
- dependency-name: libsodium-wrappers
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>