build

Add `getOnlyElement()` built in operator #3613

Job	Run time
quint-vscode-linting	1m 34s
quint-test-generated-up-to-date	1m 4s
quint-antlr-grammar	25s
quint-examples-dashboard (ubuntu-latest)	5m 29s
quint-integration-tests (ubuntu-latest)	5m 25s
quint-examples-dashboard (macos-latest)	3m 25s
quint-linting	36s
quint-integration-tests (macos-latest)	3m 55s
quint-unit-tests (ubuntu-latest)	47s
quint-unit-tests (macos-latest)	1m 11s
quint-integration-tests (windows-latest)	5m 34s
quint-vscode-plugin (ubuntu-latest)	3m 33s
quint-unit-tests (windows-latest)	1m 17s
quint-vscode-plugin (macos-latest)	5m 14s
	39m 29s

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