[Fuchsia] Disable libcxx timezone database (#65870)

tzdb is currently broken when cross compiling from non Linux to Linux.
Lets just disable it totally in our toolchain for now. We should remove
this when #65859 lands.

clang/cmake/caches/Fuchsia-stage2.cmake

@@ -181,6 +181,9 @@ foreach(target aarch64-unknown-linux-gnu;armv7-unknown-linux-gnueabihf;i386-unkn
     set(RUNTIMES_${target}_LLVM_TOOLS_DIR "${CMAKE_BINARY_DIR}/bin" CACHE BOOL "")
     set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
 
+    # TODO: Remove this once #65859 lands.
+    set(RUNTIMES_${target}_LIBCXX_ENABLE_TIME_ZONE_DATABASE OFF CACHE STRING "")
+
     # Use .build-id link.
     list(APPEND RUNTIME_BUILD_ID_LINK "${target}")
   endif()