## Changes

[Databricks SDK
0.51](https://github.com/databricks/databricks-sdk-py/releases/tag/v0.51.0)
included some breaking changes, including removal of an enumeration
where a set of well-known string constants must now be used instead:
> Breaking] Removed large, medium and small enum values for
databricks.sdk.service.serving.ServedModelInputWorkloadSize.

The change is not forward-compatible, so in addition to updating the
fixture we need to bump the minimum-required SDK version because older
versions expect the enum.

### Credits

This was earlier discovered and reported by @cornzyblack as #156.

### Linked issues

Resolves #156.
Supersedes #157.

This is also causing CI test failures on downstream projects including:

 - [databrickslabs/lsql](https://github.com/databrickslabs/lsql)
-
[databrickslabs/blueprint](https://github.com/databrickslabs/blueprint)

### Tests

- existing unit tests

* Compatibility fix for Databricks SDK 0.51
([#158](#158)). The
minimum required version of the Databricks SDK has been updated to
0.51.0 to accommodate breaking changes introduced in this version,
including the removal of certain enumeration values. Notably, the
`ServedModelInputWorkloadSize` enumeration has been replaced with
well-known string constants, prompting an update to the `create`
function to use the string constant `Small` instead of the removed
`ServedModelInputWorkloadSize.SMALL` value. This change affects the
creation of serving endpoints, which now specify workload size using a
string value, and resolves issues reported in related projects,
including test failures in downstream projects, by ensuring
compatibility with the updated SDK version.

Internally the unit tests for pytester access pytest fixtures directly.
This has been [deprecated since
4.x](https://docs.pytest.org/en/stable/deprecations.html#calling-fixtures-directly),
but the project currently contains some workarounds (in
`call_fixture()`) to do this anyway.

In pytest 8.4, the internals changed which breaks the way
`call_fixture()` accesses the underlying fixture. This PR:

 - Updates `call_fixture()` minimally so that it also works with 8.4+.
 - Adds a marker that we should fix this properly.
- Notes a promising direction for doing what we want in a supported
manner.

Resolves #165.