Agnostic, as a term to refer to a particular philosophy with respect to spirituality and mysticism, was coined by Thomas Huxley; Wikipedia gives the date as 1869 while Wiktionary says 1870, but the point is that it's from the the latter half of the nineteenth century.
Wiktionary also gives as a meaning
(computing) A software component (or other entity) that is unaware or noncommittal regarding the specific nature of the components with which it interacts
about which this site already has a couple of questions (Odd use of agnostic, Another word for agnostic when used to suggest independence through a lack of concern).
However, neither this site nor Wiktionary, nor any other source I could find with a Google search, indicate when or by whom this usage was coined. The fact that this use has its origins in computing suggests a certain timeframe, to be sure, but I am curious about the specific origins.