gh-106529: Cleanups split off gh-112134 (#112214)

- Double max trace size to 256
- Add a dependency on executor_cases.c.h for ceval.o
- Mark `_SPECIALIZE_UNPACK_SEQUENCE` as `TIER_ONE_ONLY`
- Add debug output back showing the optimized trace
- Bunch of cleanups to Tools/cases_generator/

Python/bytecodes.c

@@ -1210,6 +1210,7 @@ dummy_func(
         };
 
         specializing op(_SPECIALIZE_UNPACK_SEQUENCE, (counter/1, seq -- seq)) {
+            TIER_ONE_ONLY
             #if ENABLE_SPECIALIZATION
             if (ADAPTIVE_COUNTER_IS_ZERO(counter)) {
                 next_instr = this_instr;