devel/spirv-llvm-translator: unbreak outside poudriere after ba009f150e84

$ make
[...]

> Extracting for spirv-llvm-translator-llvm20-20.1.3

> SHA256 Checksum OK for KhronosGroup-SPIRV-LLVM-Translator-v20.1.3_GH0.tar.gz.

> No SHA256 checksum recorded for KhronosGroup-SPIRV-Headers-1.5.4.raytracing.fixed-390-g2b2e05e_GH0.tar.gz.

> No suitable checksum found for KhronosGroup-SPIRV-Headers-1.5.4.raytracing.fixed-390-g2b2e05e_GH0.tar.gz.

• Error code 1

PR: 287278
Reported by: Tom Russo