ci(release-please): add auth config to package specific npmrc file

Author: flovogt

.github/workflows/release-please.yml

@@ -35,5 +35,5 @@ jobs:
         NPM_TOKEN: ${{secrets.NPM_UI5BOT}}
       run: |
         cd ${{ matrix.path_released }}
-        npm config set "//registry.npmjs.org/:_authToken=${NPM_TOKEN}"
+        echo '//registry.npmjs.org/:_authToken=${NPM_TOKEN}' >> ./.npmrc
         npm publish --workspaces false