Fix: dataclass InitVars shouldn't be required on serialization

[sydney-runkle]

Fix pydantic/pydantic#11264

[codspeed-hq]

CodSpeed Performance Report

Merging #1602 will not alter performance

_{Comparing fix-initvar-required (3e82624) with main (b426cce)}

Summary

✅ 157 untouched benchmarks

[samuelcolvin]

We definitely need some kind of test for this change of behaviour!

We can manually build the core-schema, but we absolutely need a test or tests.

[samuelcolvin]

otherwise I think LGTM.

[samuelcolvin]

please can you add a test with just the Foo schema, and a test for Bar here.

[samuelcolvin]

and can you add a test for Foo(x=1, init_var=2)

[sydney-runkle]

please can you add a test with just the Foo schema, and a test for Bar here.

Not quite sure what you mean here - I wasn't able to repro the issue without the union.

[samuelcolvin]

I still it's still worth adding tests for the simplest cases.

[davidhewitt]

LGTM 👍