ci: make sure to use latest version of npm

Trusted publishing is supported in npm v11.5.1 and higher. The one
shipped with node 20 (in .nvmrc) is v10.x.

Author: 0x7f

.github/actions/setup/action.yml

@@ -9,6 +9,10 @@ runs:
       with:
         node-version-file: .nvmrc
 
+    - name: Update npm to latest version
+      run: npm install -g npm@latest
+      shell: bash
+
     - name: Cache dependencies
       id: yarn-cache
       uses: actions/cache@v4