Don't attempt to publish to GitHub Packages (it doesn't work)

Publishing to GPR always fails. According to
https://help.github.com/en/packages/using-github-packages-with-your-projects-ecosystem/configuring-npm-for-use-with-github-packages
this is because GPR only supports scoped npm packages. I'm not sure,
but scoping the package might not be what we want for the npm registry
(I don't think Etherpad will automatically see the scoped
package). Etherpad doesn't pay any attention to GPR, so rather than
set the scope in the GPR publish step just remove the GPR publish step
altogether.

Also see actions/setup-node#53.

.github/workflows/npmpublish.yml

@@ -1,4 +1,4 @@
-# This workflow will run tests using node and then publish a package to GitHub Packages when a release is created
+# This workflow will run tests using node and then publish a package to the npm registry when a release is created
 # For more information see: https://help.github.com/actions/language-and-framework-guides/publishing-nodejs-packages
 
 name: Node.js Package
@@ -31,17 +31,3 @@ jobs:
       - run: npm publish
         env:
           NODE_AUTH_TOKEN: ${{secrets.npm_token}}
-
-  publish-gpr:
-    needs: build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
-        with:
-          node-version: 12
-          registry-url: https://npm.pkg.github.com/
-      - run: npm ci
-      - run: npm publish
-        env:
-          NODE_AUTH_TOKEN: ${{secrets.GITHUB_TOKEN}}