Update CBMC version to 5.94 #5529

Job	Run time
benchcomp-tests	5m 43s
regression (macos-11)	1h 10m 52s
write-json-symtab-regression	18m 38s
regression (ubuntu-20.04)	38m 36s
regression (ubuntu-22.04)	43m 12s
perf	52m 9s
bookrunner	40m 42s
releasebundle-macos (macos-11)	46m 34s
releasebundle-ubuntu	31m 30s
	5h 47m 56s

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