chore: reset release version to 2.21.2

[sloloris]

Wait!

• Have you added comprehensive tests?
• Have you updated relevant data sources as well as resources?
• Have you updated the docs?

Testing

For any changes you make, please ensure your acceptance test conform to the following:

• every single new attribute is tested
• optional attributes revert to null or default values if removed
• attributes that interact interact as expected
• block values behave as expected when reordered
• nested fields on maps or list/set items function as expected. Terraform does not actually enforce most schema attributes on nested items
• each test step for a configuration is followed by a test step where ImportState and ImportStateVerify are set to true. ImportStateVerifyIgnore can be used if we explicitly expect a value to be different when imported, such as in the case of obfuscated values like API keys

LaunchDarkly Employees

For more information on how to build, test, and release, see the internal README on Confluence.