ci: detect outdated abis (#398)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Workflow Enhancement**
- Added a new GitHub Actions job for generating and validating Solidity
contract ABIs
- Introduced automated checks to ensure ABI files are up to date with
source code

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.github/workflows/solidity.yml

@@ -121,3 +121,45 @@ jobs:
         uses: github/codeql-action/upload-sarif@v3
         with:
           sarif_file: contracts/output.sarif
+
+  abis:
+    needs: init
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Restore cache
+        uses: actions/cache/restore@v4
+        with:
+          path: contracts
+          key: ci-solidity-${{ github.ref }}
+
+      - name: Restore forge
+        uses: actions/download-artifact@v4
+        with:
+          name: forge
+          path: /usr/local/bin
+
+      - run: chmod +x /usr/local/bin/forge
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+
+      - name: Install abigen
+        run: go install github.com/ethereum/go-ethereum/cmd/[email protected]
+
+      - name: Generate ABIs
+        run: dev/generate
+
+      - name: Check for ABI changes
+        working-directory: ${{ github.workspace }}
+        run: |
+          if git diff --exit-code --ignore-space-change --ignore-all-space --ignore-cr-at-eol -- contracts/pkg; then
+            echo "No ABI changes detected."
+          else
+            echo "ERROR: Generated files are not up to date. Please run 'contracts/dev/generate' and commit the changes."
+            exit 1
+          fi