Testnet preparation, migration to Sepolia, solc 0.8.24, node 18, yarn 4

.github/workflows/contracts-testing.yml

@@ -22,10 +22,16 @@ jobs:
         egress-policy: audit
 
     - name: Setup Node.js environment
-      uses: actions/setup-node@64ed1c7eab4cce3362f8c340dee64e5eaeef8f7c # v3.6.0
+      uses: actions/setup-node@v4
       with:
-        node-version: 16.x   
-
+        node-version: 18.x
+
+    - name: Enable Corepack
+      run: corepack enable
+
+    - name: Set Yarn version to Berry
+      run: yarn set version 4.2.2
+
     - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
 
     - name: Cache node modules

.gitignore

@@ -204,3 +204,5 @@ veascan-subgraph-inbox/generated/*
 veascan-subgraph-inbox/build/*
 validator-subgraph-inbox/generated/*
 validator-subgraph-inbox/build/*
+
+cache

.nvmrc

@@ -1 +1 @@
-16
+18