Bump graphiql from 0.7.8 to 1.4.7 in /samples/graphiql-client

Bumps [graphiql](https://github.com/graphql/graphiql) from 0.7.8 to 1.4.7.
- [Release notes](https://github.com/graphql/graphiql/releases)
- [Changelog](https://github.com/graphql/graphiql/blob/main/CHANGELOG.md)
- [Commits](https://github.com/graphql/graphiql/compare/v0.7.8...graphiql@1.4.7)

---
updated-dependencies:
- dependency-name: graphiql
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]