Add missing crates to the workspace (#2932)

Changes:
- add missing member to the workspace
- add CI script after the last attempt to merge it upstream failed
https://github.com/paritytech/pipeline-scripts/pull/105

Two crates are excluded from the check since they are templates
`substrate/frame/contracts/fixtures/build` and
 `substrate/frame/contracts/fixtures/contracts/common`.

Hopefully this is the last time that some crates need to be added
manually.

![meme](https://github.com/paritytech/polkadot-sdk/assets/10380170/984843ee-1c76-4126-a4fc-ff2ba1d47377)

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

.github/workflows/check-workspace.yml

@@ -0,0 +1,23 @@
+name: Check workspace
+
+on:
+  pull_request:
+    paths:
+      - "*.toml"
+  merge_group:
+
+jobs:
+  check-workspace:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.0 (22. Sep 2023)
+
+      - name: install python deps
+        run: pip3 install toml
+
+      - name: check integrity
+        run: >
+            python3 .github/scripts/check-workspace.py .
+            --exclude
+            "substrate/frame/contracts/fixtures/build" 
+            "substrate/frame/contracts/fixtures/contracts/common"