chore: add github action for foundry tests

.github/workflows/contract-tests.yml

@@ -0,0 +1,34 @@
+name: unit-tests
+
+on:
+  [push, pull_request]
+
+jobs:
+  contracts:
+    name: contracts
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      - name: Install Node.js
+        uses: actions/setup-node@v2
+        with:
+          node-version: 18
+
+      - name: Install Yarn
+        run: npm install -g yarn
+
+      - name: Install dependencies
+        run: yarn install
+
+      - name: Install Foundry
+        uses: foundry-rs/foundry-toolchain@v1
+
+      - name: Run tests
+        working-directory: packages/contracts
+        run: forge test -vvv
+
+      - name: Run snapshot
+        run: forge snapshot