fix: fixed frontend test test_torch_unfold for paddle backend

[ZenithFlux]

PR Description

• Parameter 's' of '_parse_slice' is converted to int when the function is called. Reason: Sometimes a ivy.Array was being passed as 's' which caused ivy.arange to throw an error.
• Added an assumption so that bfloat arrays are not passed to the function when testing paddle backend. Reason: When paddle backend is set, one of the functions called inside the frontend function does not accept bfloat dtype. Since a direct backend implementation is not called, I could not restrict dtypes through decorators.

Related Issue

Closes #28600

Checklist

• Did you add a function?
• Did you add the tests?
• Did you run your tests and are your tests passing?
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[Ishticode]

Hi @ZenithFlux
Thank you very much for the PR.
Two requests
the fix in parse slice might be irrelevant as this helper might disappear after merging of #28582
dtype filtering should be done on the function in the respective backend/frontend using supported or unsupported dtype decorator. Hope that makes sense :)

[ZenithFlux]

@Ishticode The decorator is not working for this case. This was acknowledged by vedpatwardhan in Discord. This is a temporary fix for now. If this fix should not be merged, I can close this PR and pick another issue.

I have removed parse slice fix.

[Ishticode]

Sure fair enough. Otherwise looks good then. Thank you very much for the PR and I will merge this soon today. :)