Change Underscore to Dash in "array_like" for fit_sandia

[ColmBhandal]

Is your feature request related to a problem? Please describe.

As noted on #765, there is one function called fit_sandia which seems to have a typo, declaring arguments as array_like (with an underscore) vs. array-like (with a dash). As noted by the author of that function, @cwhanse, there is a 99.99% probability that this was just a simple typo.

Describe the solution you'd like

Replace the 4 usages of array_like with array-like in the function fit_sandia. By doing so, this would normalise all usages of array-like across the entire project, and would thus support any efforts to solve #765 e.g. without doing this, those four usages might be lost if someone tried a "find all" in order to fix #765.

Describe alternatives you've considered

The immediately obvious alternative would be: wait until #765 is figured out. But as per the above - this issue would actually support #765, and anyway, until #765 is figured out, the contributing guidelines still do specify that array-like (dash) should be used and certainly in this case it should be used because a scalar won't work (as per the discussion on #765).

Additional context

See the comment on #765. There are 4 occurrences of array_like (underscore) in the code vs. 22 occurrences of array-like (dash).