refactor(ci): Use npm ci and remove published package install

Replaces the explicit GitHub Packages configuration and published package installation with 'npm ci' in the 'test_linux', 'test_mac', and 'test_windows' jobs within 'ci.yml'.

This streamlines the unit testing process by focusing on the source code dependencies and avoids misleadingly installing the published package in the unit test phase. The 'bundle_size' job retains its specific install as it requires the published artifact.

.github/workflows/ci.yml

@@ -46,13 +46,8 @@ jobs:
           node-version: '${{ matrix.node-version }}'
           cache: 'npm'
 
-      - name: 'Configure npm for GitHub Packages'
-        run: |
-          echo "@google-gemini:registry=https://npm.pkg.github.com/" > .npmrc
-          echo "//npm.pkg.github.com/:_authToken=${{ secrets.GITHUB_TOKEN }}" >> .npmrc
-
-      - name: 'Install dependencies for testing'
-        run: 'npm install @google-gemini/gemini-cli@${{ inputs.version }}'
+      - name: 'Install dependencies'
+        run: 'npm ci'
 
       - name: 'Run tests and generate reports'
         env:
@@ -105,13 +100,8 @@ jobs:
           node-version: '${{ matrix.node-version }}'
           cache: 'npm'
 
-      - name: 'Configure npm for GitHub Packages'
-        run: |
-          echo "@google-gemini:registry=https://npm.pkg.github.com/" > .npmrc
-          echo "//npm.pkg.github.com/:_authToken=${{ secrets.GITHUB_TOKEN }}" >> .npmrc
-
-      - name: 'Install dependencies for testing'
-        run: 'npm install @google-gemini/gemini-cli@${{ inputs.version }}'
+      - name: 'Install dependencies'
+        run: 'npm ci'
 
       - name: 'Run tests and generate reports'
         env:
@@ -231,14 +221,8 @@ jobs:
           npm config set registry https://registry.npmjs.org/
         shell: 'pwsh'
 
-      - name: 'Configure npm for GitHub Packages'
-        run: |
-          echo "@google-gemini:registry=https://npm.pkg.github.com/" > .npmrc
-          echo "//npm.pkg.github.com/:_authToken=${{ secrets.GITHUB_TOKEN }}" >> .npmrc
-        shell: 'pwsh'
-
       - name: 'Install dependencies'
-        run: 'npm install @google-gemini/gemini-cli@${{ inputs.version }}'
+        run: 'npm ci'
         shell: 'pwsh'
 
       - name: 'Run tests and generate reports'