build

refactor: remove repetitive folds in `Z3Context` #7032

Job	Run time
compiler-warnings	2m 27s
scaladoc-check	2m 55s
build-mdbook	7s
format-check	4m 5s
docker-tests	20m 55s
integration-tests (ubuntu-latest, oopsla19)	18m 49s
unit-tests (ubuntu-latest)	8m 5s
integration-tests (ubuntu-latest, arrays)	8m 38s
integration-tests (macos-latest, oopsla19)	14m 57s
unit-tests (macos-latest)	5m 24s
	1h 26m 22s

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