Bump flat and gatsby in /jamstack/gatsbyjs-material-kit#606

dependabot[bot] wants to merge 1 commit intomasterrosoftdeveloper/appseed:masterfrom

dependabot/npm_and_yarn/jamstack/gatsbyjs-material-kit/flat-and-gatsby--removedrosoftdeveloper/appseed:dependabot/npm_and_yarn/jamstack/gatsbyjs-material-kit/flat-and-gatsby--removedCopy head branch name to clipboard