chore(deps): bump @fastify/flash from 6.0.2 to 6.0.3

Bumps [@fastify/flash](https://github.com/fastify/fastify-flash) from 6.0.2 to 6.0.3.
- [Release notes](https://github.com/fastify/fastify-flash/releases)
- [Commits](fastify/fastify-flash@v6.0.2...v6.0.3)

---
updated-dependencies:
- dependency-name: "@fastify/flash"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>