ci: target baseline instead of spacemit_x60 on riscv64-linux

Doesn't seem to make much of a difference anyway, and LLVM 20 appears to still
have some miscompilations with vector and bitmanip extensions enabled.
fa445d86a1Alex Rønne Petersen committed on 8/3/2025, 9:05:04 AMparentc80aa9f
2 files changedLine totals unavailable