misc(fuzzer): Skip $internal$split_to_map in expression fuzzer (facebookincubator#15596)

Summary:
Pull Request resolved: facebookincubator#15596

Add $internal$split_to_map to the skip function list in expression fuzzer when using Presto SOT,
because this function doesn't exist in Presto.

Reviewed By: peterenescu

Differential Revision: D87596970

fbshipit-source-id: 444e7b243380419c3faa7ee6faa2af626371bef9

Author: kagamiori

velox/expression/fuzzer/ExpressionFuzzerTest.cpp

@@ -415,6 +415,7 @@ std::unordered_set<std::string> skipFunctionsSOT = {
     // https://github.com/prestodb/presto/pull/25521
     "xxhash64(varbinary,bigint) -> varbinary",
     "map_keys_by_top_n_values", // https://github.com/facebookincubator/velox/issues/14374
+    "$internal$split_to_map",
     "$internal$canonicalize",
     "$internal$contains",
     "localtime", // localtime cannot be called with paranthesis: