fix: Update CSpell version (9.6.4) #1620

Job	Run time
test-docker	11s
test-node-versions (windows-latest, 24.x)	37s
test-node-versions (24.x, ubuntu-latest)	14s
test-node-versions (20.x, ubuntu-latest)	10s
test-node-versions (22.x, ubuntu-latest)	9s
test-node-versions (25.x, ubuntu-latest)	13s
	1m 34s

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