Remove redundant CI env var from workflow

GH_TOKEN makes gh auth status pass, so the CI check in setup.sh is
never reached. The check remains in setup.sh as a safety net for
other CI environments without GH_TOKEN.

Author: mhfs

.github/workflows/ci.yml

@@ -25,7 +25,6 @@ jobs:
       - name: Run setup.sh
         run: bash setup.sh
         env:
-          CI: "true"
           GH_TOKEN: ${{ secrets.TRUSTED_SHARED_SOURCE_GITHUB_TOKEN }}
 
       - name: Install bats