Fix CQS signal facebook-unused-include-check in fbcode/folly/detail/base64_detail/tests

Reviewed By: dtolnay

Differential Revision: D76034493

fbshipit-source-id: ff2f2adffcb7e70135d27390e3301a8341f22917

Author: generatedunixname89002005287564

third-party/folly/src/folly/detail/base64_detail/tests/Base64AgainstScalarTest.cpp

@@ -15,7 +15,6 @@
  */
 
 #include <array>
-#include <exception>
 #include <limits>
 #include <optional>
 #include <random>