Release 2.5.16.0 (Oct 1, 2024) -- compared to 2.5.15.0

• ImageInput: Fix: Initialize pixels of partial tile conversion buffer to avoid possible floating point exceptionså. #4462 (by Bram Stolk)
• iv: Fix: Iv shows constant brown and GL error messages on start-up. #4451 (by David Adler)
• iv: Fix: Initialize variables before we use them. #4457 (by Bram Stolk)
• pnm: Fix: Initialize m_pfm_flip before use to avoid UB. #4446 (by Bram Stolk)
• raw: Fix: Check for nullptr in raw input plugin #4448 (by Anton Dukhovnikov)
• ci: Streamline the old MacOS-12 CI test #4465
• ci: Test against OCIO 2.4 #4467 and OpenEXR 3.3 #4466
• docs: Clarify TextureSystem::create use of imagecache when shared=true #4399
• docs: Switch license name in docs #4407
• admin: Change docs and comments references master -> main #4435