Update mlx-swift-examples repository to mlx-swift-lm

[noorbhatia]

mlx-swift-examples has been moved to mlx-swift-lm.
Update dependency URL to reflect the new location.

[mattt]

Thank you, @noorbhatia!

For posterity, here's what the mlx-swift-examples README says:

Important

MLXLMCommon, MLXLLM, MLXVLM and MLXEmbedders have moved to a new repository
containing only reusable libraries: mlx-swift-lm.

I'm glad that the maintainers have taken a step in this direction, to separate examples from reusable libraries. However, I have concerns about how exactly they've made this split. I opened an issue (ml-explore/mlx-swift-lm#6) explaining my concerns.

I'd like to wait for that to be resolved one way or another before merging, so I'll convert to draft until then.

[mattt]

I'm grateful to the mlx-swift-lm maintainers for their patience in responding to my concerns. The issue I opened is now closed, so let's move this forward.

Building an app now with MLX trait enabled, I'm now seeing this error:

Hopefully this change will fix that...

[mattt]

This change is now in effect as of 0.4.2.