Meltano

<https://github.com/meltano/sdk/pull/3731|#3731 refactor: Use more idiomatic implementation for `singer_sdk.authenticators.SingletonMeta`>
Pull request opened by <https://github.com/edgarrmondragon|edgarrmondragon>
*Summary by Sourcery*

Enhancements:
• Simplify and modernize the SingletonMeta *call* logic by delegating instance construction to the superclass when no singleton exists.
<https://github.com/meltano/sdk|meltano/sdk>

<https://github.com/meltano/sdk/pull/3731|#3731 refactor: Use more idiomatic implementation for `singer_sdk.authenticators.SingletonMeta`>
Pull request merged by <https://github.com/edgarrmondragon|edgarrmondragon>
<https://github.com/meltano/sdk|meltano/sdk>