[libc] Include cbrt in baremetal targets (#99916)

This is a follow up to #99262.

Author: petrhosek

libc/config/baremetal/arm/entrypoints.txt

@@ -236,6 +236,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.canonicalize
     libc.src.math.canonicalizef
     libc.src.math.canonicalizel
+    libc.src.math.cbrt
     libc.src.math.cbrtf
     libc.src.math.ceil
     libc.src.math.ceilf

libc/config/baremetal/riscv/entrypoints.txt

@@ -232,6 +232,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.canonicalize
     libc.src.math.canonicalizef
     libc.src.math.canonicalizel
+    libc.src.math.cbrt
     libc.src.math.cbrtf
     libc.src.math.ceil
     libc.src.math.ceilf