Move scripts used in CI to the new location (#5198)

* Move CI scripts and update references

* Update paths in .gitlab-ci.yml

* Removed outdated entries from CODEOWNERS

polkadot/scripts/ci/gitlab/test_deterministic_wasm.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+#shellcheck source=../common/lib.sh
+source "$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )/../common/lib.sh"
+
+# build runtime
+WASM_BUILD_NO_COLOR=1 cargo build --verbose --release -p kusama-runtime -p polkadot-runtime -p westend-runtime
+# make checksum
+sha256sum target/release/wbuild/*-runtime/target/wasm32-unknown-unknown/release/*.wasm > checksum.sha256
+# clean up - FIXME: can we reuse some of the artifacts?
+cargo clean
+# build again
+WASM_BUILD_NO_COLOR=1 cargo build --verbose --release -p kusama-runtime -p polkadot-runtime -p westend-runtime
+# confirm checksum
+sha256sum -c checksum.sha256