fix(sessions): `storeEnvelope` updates session when passed unhandled event #8331

Job	Run time
UI Tests for SwiftUI on iPhone 8 (15.2) Simulator	4m 55s
UI Tests for SwiftUI on iPhone 8 (16.1) Simulator	9m 28s
UI Tests for ios_objc on Simulators	5m 0s
iOS-Swift UI Tests iPhone 8 (15.5)	6m 57s
UI Tests with Address Sanitizer	28m 27s
UI Tests for tvos_swift on Simulators	4m 16s
iOS-Swift UI Tests iPhone 14 (16.4)	10m 41s
iOS-Swift UI Tests iPhone 15 (17.2)	9m 28s
	1h 19m 12s

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