coeff for non-integer powers fails

[NAThompson]

To reproduce:

from sympy import * 
i = symbols('i', integer=True)
α = symbols('α', real=True)
x = symbols('x', real=True, positive=True)
c = symbols('c', real=True)
f = c*pow(x, i + α)
expr = simplify(collect(diff(f, x), x))
print(latex(expr)) # works as expected
co = expr.coeff(x, i + α - 1)

Visual inspection of the print allows us to easily determine the result should be (i+α)c, but instead we get:

Traceback (most recent call last):
  File "~/lib/python3.12/site-packages/sympy/utilities/misc.py", line 555, in as_int
    return operator.index(n)
           ^^^^^^^^^^^^^^^^^
TypeError: 'Add' object cannot be interpreted as an integer

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "reproduce.py", line 9, in <module>
    co = expr.coeff(x, i + α - 1)
         ^^^^^^^^^^^^^^^^^^^^^^^^
  File "~/lib/python3.12/site-packages/sympy/core/expr.py", line 1461, in coeff
    n = as_int(n)
        ^^^^^^^^^
  File "~/lib/python3.12/site-packages/sympy/utilities/misc.py", line 557, in as_int
    raise ValueError('%s is not an integer' % (n,))
ValueError: i + α - 1 is not an integer

Now, I concede that this is probably just a feature request, but nonetheless I figured I'd see if someone put the assert in there just for safety, even though real-valued arguments should work just fine.

Other information:

$ pip show sympy
Version: 1.12