That's not what geolocation is. Geolocation data is an optional feature of
some image formats (JPEG, in particular; I don't know of any others) which
tells where a photo was taken.
I'm not familiar with GIMP, but the libraries you're worried about sound to
me like libraries that GIMP uses to read this geolocation data. This isn't
spyware.
You also seem to have a fear of using libraries for little reason than "some
proprietary software uses it". Using that logic, you would also avoid OpenGL,
which is often used for proprietary game engines. Heck, you would have to
avoid just about anything, because C and C++ are popular for proprietary
programs too, not just free programs. Just because some proprietary software
uses a library doesn't mean the library is malicious or proprietary. WebKit
is a standard layout engine for web browsers, with Google Chrome and Safari
being the most well-known examples of browsers that use it.
