Get node version from nvmrc in github CI

Author: jsimck

.github/actions/prepare-workspace/action.yml

@@ -7,7 +7,7 @@ runs:
     - uses: actions/checkout@v4
     - uses: actions/setup-node@v4
       with:
-        node-version: 20
+        node-version-file: '.nvmrc'
         registry-url: 'https://registry.npmjs.org'
         cache: 'npm'