fix: add GITHUB_TOKEN to build code-server job

Downloading @vscode/ripgrep is failing only in CI so adding this
environment variable to see if it increases the rate limit.

Ref: https://github.com/microsoft/vscode-ripgrep#github-api-limit-note

.github/workflows/build.yaml

@@ -179,6 +179,8 @@ jobs:
         run: yarn --frozen-lockfile
 
       - name: Build code-server
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: yarn build
 
       # Get Code's git hash.  When this changes it means the content is