Incremental SMT2: Remove unnecessary #if 0 for floating-point modulo

[tautschnig]

All floating-point operations are handled via an earlier branch, even if changed to #if 1 it would remain dead code. #8922 added full floating-point support to the incremental SMT2 back-end.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.60%. Comparing base (01ebe42) to head (9e494db).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #9027   +/-   ##
========================================
  Coverage    80.59%   80.60%           
========================================
  Files         1711     1711           
  Lines       189454   189454           
  Branches        73       73           
========================================
+ Hits        152697   152700    +3     
+ Misses       36757    36754    -3     

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