fix: deprecated flag

Author: QGarchery

certora/confs/ExactMath.conf

@@ -9,7 +9,7 @@
     "-depth 5",
     "-mediumTimeout 5",
     "-timeout 3600",
-    "-adaptiveSolverConfig false",
+    "-backendStrategy singlerace",
     "-smt_nonLinearArithmetic true",
     "-solvers [z3:def{randomSeed=1},z3:def{randomSeed=2},z3:def{randomSeed=3},z3:def{randomSeed=4},z3:def{randomSeed=5},z3:def{randomSeed=6},z3:def{randomSeed=7},z3:lia2]"
   ],

certora/confs/LiquidateBuffer.conf

@@ -9,7 +9,7 @@
     "-depth 5",
     "-mediumTimeout 20",
     "-timeout 3600",
-    "-adaptiveSolverConfig false",
+    "-backendStrategy singlerace",
     "-smt_nonLinearArithmetic true",
     "-destructiveOptimizations twostage",
     "-solvers [z3:def{randomSeed=1},z3:def{randomSeed=2},z3:def{randomSeed=3},z3:def{randomSeed=4},z3:def{randomSeed=5},z3:def{randomSeed=6},z3:def{randomSeed=7},z3:def{randomSeed=8},z3:def{randomSeed=9},z3:def{randomSeed=10}]"