OpenImageIO: Unbounded recursion in FITS header parser leads to stack overflow

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1, A crafted fits stream containing consecutive 2880-byte header blocks without the mandatory end keyword makes fitsinput::read_fits_header() call itself without a depth bound. repeated recursive parsing exhausts the application stack, resulting in denial of service. The affected implementation is identified by src/fits.imageio/fitsinput.cpp, FitsInput::read_fits_header(), END keyword, and 2880-byte FITS header blocks, which define the relevant source path, functions, state, and trigger. This issue is fixed in versions 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1.