Use eng/common/build.sh since normal build.sh always builds

Author: akoeplinger

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

@@ -24,11 +24,11 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Do an initial restore to ensure all dependencies are restored
         run: |
-          ./build.sh -restore
+          ./eng/common/build.sh --restore
       - name: Put repo-local dotnet install on PATH
         run: |
           echo "PATH=$PWD/.dotnet:$PATH" >> $GITHUB_ENV
 
       - name: Check dotnet version
         run: |
-          dotnet --version
+          dotnet --version