Is the constant pi (not Raspberry) ever used in general computer science?
The $\pi$ constant is not used in theoretical computer science due to some intrinsic value or utility of the constant itself. 
However, it is (obviously) used in the simulations of physical systems or mathematical equations in which it appears. Precisely for this reason, one of the efforts that computer scientist and mathematicians have made in this regard was to identify new methods and algorithms to be able to generate as many digits of its decimal expansion as possible.

If today we know $\pi$ up to 31.4 trillion decimal places 
we owe it to the computational power of electronic systems.