[RISCV] Regen ctselect tests, replace RVV vector test with placeholder
The core PR's new CT_SELECT legalizer expansion currently fails for
several scalable-vector cases on RISC-V V extension (basic/load/mixed
patterns hit "Unexpected illegal type!" in LegalizeOp).
Replace the RVV scalable test file with a passing placeholder
documenting the issue. Regen CHECK lines for the other ctselect tests
to match the new core codegen.