ci: raise the log level threshold of spirv logs
Avoid the wall of "Unsupported SPIR-V capability" warnings in CI job log, hiding away useful output:
ERROR - dEQP error: SPIR-V WARNING:
ERROR - dEQP error: In file ../src/compiler/spirv/spirv_to_nir.c:4779
ERROR - dEQP error: Unsupported SPIR-V capability: SpvCapabilityDrawParameters (4427)
ERROR - dEQP error: 28 bytes into the SPIR-V binary