chore: Remove nested slices SSA and ACIR codegen #2412

Job	Run time
build-acvm-js	4m 26s
build-nargo	2m 13s
build-noirc-abi	4m 32s
ACVM JS (Browser)	1m 11s
ACVM JS (Node.js)	42s
Noir JS	1m 29s
build-noir-wasm	2m 22s
noirc_abi	43s
noir-js-backend-barretenberg	41s
noir_codegen	58s
Integration Tests	8m 42s
noir_wasm	1m 1s
End	1s
	29m 1s

Provide feedback