DOC: A typo in ValueError raised by signal.iirdesign

[budjen-jovan]

Issue with current documentation:

Currently, in signal.iirdesign there is an error message being thrown:
raise ValueError("wp and ws must have one or two elements each, and" f"the same shape, got {wp.shape} and {ws.shape}")
There is a missing whitespace between the two strings (github messes up the formatting, I can't figure out how to format this properly.
A resulting error message being thrown is

ValueError: wp and ws must have one or two elements each, andthe same shape, got (4,) and (2,)

Idea or request for content:

Again, looking at the existing solutions in the code (although they are not very consistent about this), I suggest adding a whitespace to the end of the first string or the beginning of the other string. There is a slight styling problem where the two solutions are being used interchangably - it doesn't break functionality in any way, it's just not pretty to look at. I suppose I can fix that, it's trivial, but I'm not sure if that's a change worth doing, do let me know.

Additional context (e.g. screenshots, GIFs)

No response

[lucascolley]

PR welcome if you would like to fix it!

[budjen-jovan]

Absolutely, will do in a sec