lower the input limits, I might need to push a config change to oss-fuzz as well to lower the max input size

fuzz/unpack_pack_fuzzer.cpp

@@ -4,7 +4,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   try {
     // NOTE(derwolfe): by default the limits are set at 2^32-1 length. I'm
     // setting these at far smaller values to avoid OOMs
-    const int test_limit = 10000;
+    const int test_limit = 1000;
     msgpack::object_handle unpacked = msgpack::unpack(reinterpret_cast<const char *>(data),
                                                       size,
                                                       nullptr,