fix: yarn install

.gitea/workflows/build.yaml

@@ -20,10 +20,11 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: "20"
-          cache: "yarn"
 
-      - name: Enable Corepack (Yarn 4)
+      - name: Enable Corepack and Yarn
-        run: corepack enable
+        run: |
+          corepack enable
+          corepack prepare yarn@stable --activate
 
       - name: Install dependencies
         run: yarn install --immutable