Throwing std::exception's instead of plain int's in the tests.

test/ScopeFailTest.cpp

     {
         REQUIRE_CALL(m, deleter());
         [[maybe_unused]] auto guard = sr::scope_fail{deleter};
-        throw 3;
+        throw std::exception{};
     }
     catch( ... )
     {
 {
     try
     {
-        throw 3;
+        throw std::exception{};
     }
     catch( ... )
     {

test/ScopeSuccessTest.cpp

     try
     {
         [[maybe_unused]] auto guard = sr::scope_success{deleter};
-        throw 3;
+        throw std::exception{};
     }
     catch( ... )
     {
 {
     try
     {
-        throw 3;
+        throw std::exception{};
     }
     catch( ... )
     {