Run node tests

Currently we have a job for each supported version of Bitcoin Core and
in it we run the integration tests.

Note also that `node` is currently not a member of the workspace. So it
misses out on all the benefits of `run_task` (e.g., linting).

However `node` cannot be directly run using `run_task` because of its
unusual features - it requires a version feature to build.

Add a script to lint and one to run tests then call these from CI.

While we are at it update the justfile now that `node` can be linted and
formatted as part of workspace commands. Also update the
`update-lock-files` script.

Author: tcharding

.github/workflows/rust.yaml

@@ -119,7 +119,7 @@ jobs:
       - name: "Set dependencies"
         run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
       - name: "Run test script"
-        run: ./maintainer-tools/ci/run_task.sh lint
+        run: contrib/lint.sh
 
   Docs:
     name: Docs - stable toolchain
@@ -232,4 +232,4 @@ jobs:
       - name: "Select toolchain"
         uses: dtolnay/rust-toolchain@stable
       - name: "Run integration tests"
-        run: cd integration_test && cargo test --features=${{ matrix.feature }}
+        run: ./contrib/version_specific_tests.sh ${{ matrix.feature }}