internal/rosa/cmake: remove variant

This has no effect outside formatting of name and is a remnant of the old llvm helpers.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/stage0.go

@@ -9,9 +9,9 @@ import (
 func (t Toolchain) newStage0() (pkg.Artifact, string) {
 	return t.New("rosa-stage0", 0, []pkg.Artifact{
 		t.Load(Musl),
-		t.Load(LLVMCompilerRT),
+		t.Load(CompilerRT),
 		t.Load(LLVMRuntimes),
-		t.Load(LLVMClang),
+		t.Load(Clang),
 
 		t.Load(Zlib),
 		t.Load(Bzip2),