fix: contracts testing workflow

Author: jaybuidl

.github/workflows/contracts-testing.yml

@@ -39,22 +39,21 @@ jobs:
           registry.npmjs.org:443
           54.185.253.63:443
 
+    - name: Set up corepack (for yarn)
+      run: |
+        corepack enable
+        corepack prepare yarn@4.5.1 --activate
+        yarn set version 4.5.1
+  
     - name: Setup Node.js environment
       uses: actions/setup-node@39370e3970a6d050c480ffad4ff0ed4d3fdee5af # v4.1.0
       with:
-        node-version: 18.x   
+        node-version: 20.x   
+        cache: yarn
 
     - 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
@@ -70,7 +69,6 @@ jobs:
 
     - name: Install contracts dependencies
       run: |
-        yarn set version 4.5.1
         yarn workspace @kleros/kleros-v2-contracts install
 
     - name: Install Foundry