tests: replace many .unwrap()s with ?s using eyre#9111

glehmann wants to merge 7 commits intojj-vcs:mainjj-vcs/jj:mainfrom

glehmann:gln/refactor-unwrap-to-question-mark-in-tests-lqywglehmann/jj:gln/refactor-unwrap-to-question-mark-in-tests-lqywCopy head branch name to clipboard