chore: make clippy warnings errors in ci_checks script (FuelLabs#…

…4682)

## Description
closes FuelLabs#4678.

This PR updates `ci_checks.sh` so that `clippy` warnings are treated as
errors, just like the CI. This improves the correspondence between ci
and the `ci_checks.sh` script.

ci_checks.sh

@@ -16,7 +16,7 @@
 # `cargo install cargo-generate`
 # `cargo install cargo-udeps`
 
-cargo clippy --all-features --all-targets &&
+cargo clippy --all-features --all-targets -- -D warnings &&
 cargo sort -w --check &&
 cargo sort -w --check templates/sway-test-rs/template &&
 cargo fmt --all -- --check &&