[BugFix] use maybe_unused to supress unused return result (#58419)

Signed-off-by: Kevin Cai <[email protected]>
(cherry picked from commit 7821437)

Author: kevincai

be/src/util/simdjson_util.h

@@ -36,7 +36,7 @@ class SimdjsonParser {
     SimdjsonParser() {
         // The `_parser` is only used for `unescape`ing, which touches nothing of the parser's internal structure,
         // so the capacity doesn't matter.
-        (void)_parser.allocate(0);
+        [[maybe_unused]] auto err = _parser.allocate(0);
     }
     ~SimdjsonParser() = default;