chore(dev-deps): bump @salesforce/cli-plugins-testkit #1608

Job	Run time
yarn-lockfile-check / lockfile-check	9s
linux-unit-tests / determine-node-versions	3s
linux-unit-tests / prevent-typescript-dependency / prevent-typescript-dependency	17s
linux-unit-tests / linux-unit-tests (current)	1m 34s
linux-unit-tests / linux-unit-tests (lts/*)	1m 37s
linux-unit-tests / linux-unit-tests (lts/-1)	1m 44s
windows-unit-tests / determine-node-versions	2s
nuts (ubuntu-latest, yarn test:nuts:package) / yarn test:nuts:package	8m 54s
nuts (windows-latest, yarn test:nuts:package) / yarn test:nuts:package	18m 40s
windows-unit-tests / windows-unit-tests (current)	3m 4s
windows-unit-tests / windows-unit-tests (lts/*)	3m 19s
windows-unit-tests / windows-unit-tests (lts/-1)	5m 25s
	44m 48s

Provide feedback