fix(flake): stop flake.nix removing ignored-tests.txt #4412

Job	Run time
build-acvm-js	2m 31s
build-nargo	2m 16s
build-noirc-abi	2m 27s
build-noir-wasm	2m 35s
noir-js-backend-barretenberg	48s
noirc_abi	44s
ACVM JS (Node.js)	36s
Noir JS	1m 42s
ACVM JS (Browser)	1m 30s
noir_codegen	57s
noir_wasm	1m 8s
Integration Tests (Node)	5m 23s
Integration Tests (Browser)	5m 7s
End	1s
	27m 45s

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