Fix sources of test instability #1048

Job	Run time
test (ubuntu-latest)	2m 12s
test (ubuntu-latest)	2m 32s
test (macos-latest)	7m 25s
test (macos-latest)	3m 47s
test-install (ubuntu-latest, bash)	4s
test-install (ubuntu-latest, bash)	5s
test (windows-latest)	4m 51s
test (windows-latest)	6m 37s
test-install (ubuntu-latest, sh)	6s
test-install (ubuntu-latest, sh)	7s
test-install (ubuntu-latest, zsh, sudo apt update && sudo apt install -y zsh)	17s
test-install (ubuntu-latest, zsh, sudo apt update && sudo apt install -y zsh)	15s
test-install (ubuntu-latest, fish, sudo apt update && sudo apt install -y fish)	16s
test-install (ubuntu-latest, fish, sudo apt update && sudo apt install -y fish)	20s
test-install (macos-latest, bash)	13s
test-install (macos-latest, bash)	12s
test-install (macos-latest, sh)	12s
test-install (macos-latest, sh)	14s
test-install (macos-latest, zsh, brew update && brew install zsh)	56s
test-install (macos-latest, zsh, brew update && brew install zsh)	1m 14s
test-install (macos-latest, fish, brew update && brew install fish)	45s
test-install (macos-latest, fish, brew update && brew install fish)	1m 1s
	33m 41s

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