update missing targets list

Author: BoxyUwU

src/bootstrap/src/core/sanity.rs

@@ -34,15 +34,8 @@ pub struct Finder {
 //
 // Targets can be removed from this list once they are present in the stage0 compiler (usually by updating the beta compiler of the bootstrap).
 const STAGE0_MISSING_TARGETS: &[&str] = &[
-    "aarch64-unknown-helenos",
-    "i686-unknown-helenos",
-    "x86_64-unknown-helenos",
-    "powerpc-unknown-helenos",
-    "sparc64-unknown-helenos",
     // just a dummy comment so the list doesn't get onelined
-    "riscv64gc-unknown-redox",
     "riscv64im-unknown-none-elf",
-    "hexagon-unknown-qurt",
 ];
 
 /// Minimum version threshold for libstdc++ required when using prebuilt LLVM