fix(ci): Add npm config step to e2e_linux job

Adds the 'Configure npm for GitHub Packages' step to the 'e2e_linux' job in 'e2e.yml'.

This was missing, causing the job to fail when trying to install the test package from the GitHub Packages registry.

.github/workflows/e2e.yml

@@ -48,6 +48,11 @@ jobs:
         with:
           ref: '${{ github.event.inputs.branch_ref || github.ref }}'
 
+      - name: 'Configure npm for GitHub Packages'
+        run: |
+          echo "@google-gemini:registry=https://npm.pkg.github.com/" > .npmrc
+          echo "//npm.pkg.github.com/:_authToken=${{ secrets.GITHUB_TOKEN }}" >> .npmrc
+
       - name: 'Install dependencies'
         run: 'npm install @google-gemini/gemini-cli@${{ inputs.version }}'