fix: call `fs.createReadStream` lazily #1416

Job	Run time
test_matrix (10, macos-latest)	55s
Lint TypeScript declaration files	30s
Format	17s
test_matrix (10, ubuntu-latest)	25s
Lint JavaScript	13s
test_matrix (10, windows-latest)	1m 23s
test_matrix (12, macos-latest)	49s
test_matrix (12, ubuntu-latest)	31s
test_matrix (12, windows-latest)	1m 25s
test_matrix (14, macos-latest)	55s
test_matrix (14, ubuntu-latest)	28s
test_matrix (14, windows-latest)	1m 22s
test_matrix (16, macos-latest)	40s
test_matrix (16, ubuntu-latest)	35s
test_matrix (16, windows-latest)	1m 5s
test_matrix (18, macos-latest)	44s
test_matrix (18, ubuntu-latest)	23s
test_matrix (18, windows-latest)	1m 31s
test_matrix (20, macos-latest)	43s
test_matrix (20, ubuntu-latest)	25s
test_matrix (20, windows-latest)	1m 6s
test	1s
	16m 26s

Provide feedback