[libc] Include tan in the baremetal configuration (llvm#97921)

This is available as of llvm#97489.

Author: petrhosek

libc/config/baremetal/arm/entrypoints.txt

@@ -386,6 +386,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.sqrt
     libc.src.math.sqrtf
     libc.src.math.sqrtl
+    libc.src.math.tan
     libc.src.math.tanf
     libc.src.math.tanhf
     libc.src.math.trunc

libc/config/baremetal/riscv/entrypoints.txt

@@ -381,6 +381,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.sqrt
     libc.src.math.sqrtf
     libc.src.math.sqrtl
+    libc.src.math.tan
     libc.src.math.tanf
     libc.src.math.tanhf
     libc.src.math.trunc