fix: contracts testing workflow

Author: jaybuidl

.github/workflows/contracts-testing.yml

@@ -47,7 +47,15 @@ jobs:
     - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       with:
         submodules: recursive
+
+    - name: Set up corepack (for yarn)
+      run: corepack enable
 
+    - name: Get yarn cache
+      uses: actions/setup-node@39370e3970a6d050c480ffad4ff0ed4d3fdee5af # v4.1.0
+      with:
+        cache: yarn
+  
     - name: Cache node modules
       uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
       env: