fix: pin version of node 20 to avoid vite bug

The vite build was failing because of a bug in node v20.6.

I have pinned v20.5, as there seems to be an issue with
vite and node 20.6. This should be undone once the issue is resolved on
the node/vite side.

.github/workflows/ci.yml

@@ -49,7 +49,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [16, 18, 20]
+        node: [16, 18, 20.5]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2