Bump execa from 5.1.1 to 9.3.1 #1879

Job	Run time
Test addon (floating dependencies) (ember)	1m 24s
Test compatibility (ember-lts-4.4)	2m 16s
Test addon (floating dependencies) (node)	1m 11s
Lint files	3m 3s
Test addon (locked dependencies) (ember)	59s
Test compatibility (ember-lts-4.8)	2m 14s
Test addon (floating dependencies) (test-apps)	1m 16s
Test compatibility (ember-lts-4.12)	2m 15s
Test addon (locked dependencies) (node)	43s
Test compatibility (ember-release)	2m 18s
Test addon (locked dependencies) (test-apps)	59s
Test compatibility (ember-beta)	2m 11s
Test compatibility (ember-canary)	2m 20s
Test compatibility (embroider-safe)	2m 13s
Deploy app	0s
	25m 22s

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