Unpin Node v20 since nodejs/node#49497 is fixed

Author: bjoluc

.github/workflows/build.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [16, 18, "20.5"]
+        node: [16, 18, 20]
 
     steps:
       - uses: actions/checkout@v4

.github/workflows/release.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v3
         with:
-          node-version: "20.5"
+          node-version: 20
           cache: npm
 
       - name: Install dependencies