Backports some fixes to reported security vulnerabilities in Godot's TGA loader, and the tinyexr dependency.

CVE-2021-26825 - An integer overflow issue exists in Godot Engine up to v3.2 that can be triggered when loading specially crafted.TGA image files. The vulnerability exists in ImageLoaderTGA::load_image() function at line: const size_t buffer_size = (tga_header.image_width * tga_header.image_height) * pixel_size; The bug leads to Dynamic stack buffer overflow. Depending on the context of the application, attack vector can be local or remote, and can lead to code execution and/or system crash.

CVE-2021-26826 - A stack overflow issue exists in Godot Engine up to v3.2 and is caused by improper boundary checks when loading .TGA image files. Depending on the context of the application, attack vector can be local or remote, and can lead to code execution and/or system crash.

CVE-2022-38529 - tinyexr commit 0647fb3 was discovered to contain a heap-buffer overflow via the component rleUncompress.