Meltano

<https://github.com/meltano/sdk/pull/3572|#3572 docs: Remove redundant usage of `typing.ClassVar` in examples>
Pull request opened by <https://github.com/edgarrmondragon|edgarrmondragon>
SSIA

*Summary by Sourcery*

Documentation:
• Simplify schema-related code examples in the schema sources guide by removing redundant ClassVar usage and type annotations.
<https://github.com/meltano/sdk|meltano/sdk>

<https://github.com/meltano/sdk/pull/3572|#3572 docs: Remove redundant usage of `typing.ClassVar` in examples>
Pull request merged by <https://github.com/edgarrmondragon|edgarrmondragon>
<https://github.com/meltano/sdk|meltano/sdk>