fix(infra): downgrade to node v20.5.x

This fix is needed in order to be able to have green tests.
Currently Node.js v20.6 (which is the most recent at the moment) has some
issues with babel and esmock breaks.

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
     name: Unit and Integration
     strategy:
       matrix:
-        version: [16, 18, 20]
+        version: [16, 18, 20.5]
         os: [ubuntu-22.04, windows-2022, macos-13]
     runs-on: ${{ matrix.os }}
     steps: