Upgrade libcxx and use c++ 23

1. Meet latest glaze's requirements, and upgrade it
2. Get rid of glaze_write_json to avoid using iostream, which made binary size increased. Use C methods instead.

Signed-off-by: GarfieldHan <2652609017@qq.com>

gradle/libs.versions.toml

@@ -7,6 +7,7 @@ annotation = "1.8.0"
 [libraries]
 annotation = { module = "androidx.annotation:annotation", version.ref = "annotation" }
 bcpkix-jdk18on = { module = "org.bouncycastle:bcpkix-jdk18on", version.ref = "bcpkix-jdk18on" }
+cxx = { module = "org.lsposed.libcxx:libcxx", version = "27.0.12077973" }
 
 [plugins]
 agp-app = { id = "com.android.application", version.ref = "agp" }