use update instead of instantiate

Author: jkrumbiegel

.github/workflows/test-smokes.yml

@@ -185,7 +185,7 @@ jobs:
         run: echo "QUARTO_JULIA_PROJECT=$(GITHUB_WORKSPACE)/qnr" >> $GITHUB_ENV
 
       - name: Instantiate QuartoNotebookRunner
-        run: julia --project=$GITHUB_WORKSPACE/qnr -e 'using Pkg; Pkg.instantiate()'
+        run: julia --project=$GITHUB_WORKSPACE/qnr -e 'using Pkg; Pkg.update()'
 
       - name: Cache Julia Packages
         uses: julia-actions/cache@v2