fix: upgrade standard-version from 9.0.0 to 9.1.0 (#535)

Snyk has created this PR to upgrade standard-version from 9.0.0 to 9.1.0.

See this package in npm:
https://www.npmjs.com/package/standard-version

See this project in Snyk:
https://app.snyk.io/org/nodeshift-agg/project/0569fa2f-39b2-4a6a-9bdc-8ac878d28a88?utm_source=github&utm_medium=upgrade-pr

Co-authored-by: snyk-bot <snyk-bot@snyk.io>