Do not remove the last digit from float values (#5974)

Trailing zeros are already removed inside the function FloatToString,
that is called immediately before the lines deleted by this commit.
diff --git a/src/idl_parser.cpp b/src/idl_parser.cpp
index 611f28d..a77100a 100644
--- a/src/idl_parser.cpp
+++ b/src/idl_parser.cpp
@@ -3285,10 +3285,6 @@
     value.constant = NumToString(field->default_integer());
   } else if (IsFloat(value.type.base_type)) {
     value.constant = FloatToString(field->default_real(), 16);
-    size_t last_zero = value.constant.find_last_not_of('0');
-    if (last_zero != std::string::npos && last_zero != 0) {
-      value.constant.erase(last_zero, std::string::npos);
-    }
   }
   deprecated = field->deprecated();
   required = field->required();