build(deps): Bump singer-sdk from 0.40.0a2 to 0.40.0

Bumps [singer-sdk](https://github.com/meltano/sdk) from 0.40.0a2 to 0.40.0.
- [Release notes](https://github.com/meltano/sdk/releases)
- [Changelog](https://github.com/meltano/sdk/blob/main/CHANGELOG.md)
- [Commits](meltano/sdk@v0.40.0a2...v0.40.0)

---
updated-dependencies:
- dependency-name: singer-sdk
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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