Bump syn from 2.0.107 to 2.0.108 (#186)

Bumps [syn](https://github.com/dtolnay/syn) from 2.0.107 to 2.0.108. - [Release notes](https://github.com/dtolnay/syn/releases) - [Commits](dtolnay/syn@2.0.107...2.0.108) --- updated-dependencies: - dependency-name: syn dependency-version: 2.0.108 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]