Support building runsc with legacy GNU linker

This commit enables building with the legacy GNU linker that emits the
.note.gnu.property section which conflicts with the .crblob section
inside the sysmsg linker script.

pkg/sentry/platform/systrap/sysmsg/pie.lds.S

@@ -34,6 +34,6 @@ SECTIONS
         } =0x00000000,
 
         /DISCARD/ : {
-                *(.interp) *(.gnu.hash) *(.hash) *(.dynamic) *(.dynsym) *(.dynstr) *(.rela.dyn) *(.eh_frame)
+                *(.interp) *(.gnu.hash) *(.hash) *(.dynamic) *(.dynsym) *(.dynstr) *(.rela.dyn) *(.eh_frame) *(.note.gnu.property)
         }
 }