Bump parity-scale-codec from 3.6.3 to 3.6.4 (#2909)

Bumps [parity-scale-codec](https://github.com/paritytech/parity-scale-codec) from 3.6.3 to 3.6.4.
- [Release notes](https://github.com/paritytech/parity-scale-codec/releases)
- [Changelog](https://github.com/paritytech/parity-scale-codec/blob/master/CHANGELOG.md)
- [Commits](https://github.com/paritytech/parity-scale-codec/compare/v3.6.3...parity-scale-codec-v3.6.4)

---
updated-dependencies:
- dependency-name: parity-scale-codec
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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