Fix side effects in `if-let` expressions #16446

Job	Run time
build-reference-examples	1m 50s
build-forc-doc-sway-lib-std	4m 5s
build-forc-test-project	12m 23s
build-mdbook	6m 41s
build-sway-lib-core	1m 31s
build-sway-examples	1m 58s
build-sway-lib-std	2m 15s
cargo-build-workspace	6m 21s
cargo-clippy	1m 18s
cargo-fmt-check	19s
cargo-run-e2e-test	42m 28s
cargo-run-e2e-test-evm	4m 42s
cargo-run-e2e-test-midenvm	5m 14s
cargo-test-workspace	14m 48s
cargo-test-lib-std	3m 18s
cargo-toml-fmt-check	24s
cargo-unused-deps-check	6m 16s
forc-fmt-check-panic	2m 24s
forc-fmt-check-sway-examples	1m 35s
forc-pkg-fuels-deps-check	21s
forc-run-benchmarks	5m 14s
forc-unit-tests	2m 44s
pre-publish-check	0s
notify-slack-on-failure	1s
build-publish-master-image	0s
publish	0s
build-publish-release-image	0s
Build and upload forc binaries to release	0s
	2h 8m 10s

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