[Bug] Deprecation warning for custom microbatch macros is being fired incorrectly

[QMalcolm]

Is this a new bug in dbt-core?

• I believe this is a new bug in dbt-core
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

A deprecation warning about custom microbatch marcos is issued IFF all the following are true

1. a project DOESNT have a custom "microbatch" macro
2. the require_batched_execution_for_custom_microbatch_strategy is set to False
3. the project has a "microbatch" model

Expected Behavior

A deperecation warning about custom microbatch macros should only be issued IFF all the following are true

1. a project DOES have a custom "microbatch" macro
2. the require_batched_execution_for_custom_microbatch_strategy is set to False
3. the project has a "microbatch" model

Steps To Reproduce

1. get dbt-postgres 1.9.0b1
2. create a microbatch model in your project (without a custom "microbatch" macro)
3. run dbt run
4. observe the deprecation warning

Relevant log output

No response

Environment

- OS:
- Python:
- dbt:

Which database adapter are you using with dbt?

No response

Additional Context

No response