Fix Ideogram 4 Callback Handling and Tests

[dg845]

What does this PR do?

This PR fixes a bug in Ideogram4Pipeline.__call__ where a dict comprehension was used to get callback_kwargs. On Python versions before 3.12 (PEP 709), this means that callback_kwargs doesn't correctly get local variables like latents. The PR fixes this by using the standard for loop pattern used by most other pipelines (e.g. Flux 2), which works on all Python versions:

diffusers/src/diffusers/pipelines/flux2/pipeline_flux2.py

Lines 995 to 999 in 2371082

	if callback_on_step_end is not None:
	callback_kwargs = {}
	for k in callback_on_step_end_tensor_inputs:
	callback_kwargs[k] = locals()[k]
	callback_outputs = callback_on_step_end(self, i, t, callback_kwargs)

It also unskips the Ideogram 4 callback tests, which pass after the fix.

Fixes #14617

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@sayakpaul
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[sayakpaul]

Let's go!