fix: remove invalid package manager field #524

Job	Run time
Lint using ESLint	25s
Test / prepare-node-matrix	7s
Test / test (18, ubuntu-latest)	9m 29s
Test / test (18, macos-latest)	3m 8s
Test / test (18, windows-latest)	6m 44s
Test / test (16, ubuntu-latest)	2m 3s
Test / test (16, macos-latest)	2m 13s
Test / test (16, windows-latest)	5m 25s
Test / test (20, ubuntu-latest, experimental)	2m 15s
Test / test (20, macos-latest, experimental)	2m 35s
Test / test (20, windows-latest, experimental)	5m 3s
	39m 27s

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