Only do a restore in copilot-setup-steps.yml to make sure a build error doesn't break Copilot

Author: akoeplinger

.github/workflows/copilot-setup-steps.yml

@@ -22,9 +22,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      - name: Do an initial build to ensure all dependencies are restored
+      - name: Do an initial restore to ensure all dependencies are restored
         run: |
-          ./build.sh
+          ./build.sh -restore
       - name: Put repo-local dotnet install on PATH
         run: |
           echo "PATH=$PWD/.dotnet:$PATH" >> $GITHUB_ENV