GCC 13 stopped transitively including some headers
(such as `cstdint`) in various scenarios, causing
the build of `ite-backlight` to fail on nixos-unstable.
This change temporarily pulls in a commit from an open
upstream PR [1] that fixes the mentioned build issue via
`fetchpatch` until said PR gets merged.
[1]: https://github.com/hexagonal-sun/ite-backlight/pull/2