Bump hashicorp/vault in /example/vault/environments/local

Bumps [hashicorp/vault](https://github.com/hashicorp/terraform-provider-vault) from 3.20.0 to 3.20.1.
- [Release notes](https://github.com/hashicorp/terraform-provider-vault/releases)
- [Changelog](https://github.com/hashicorp/terraform-provider-vault/blob/main/CHANGELOG.md)
- [Commits](hashicorp/terraform-provider-vault@v3.20.0...v3.20.1)

---
updated-dependencies:
- dependency-name: hashicorp/vault
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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