Remove redundant bash verification on Windows

The PowerShell script already verifies Quarto is available with
Get-Command. The bash check was redundant and failing because
GITHUB_PATH updates only take effect in subsequent steps, not
within the same step where the PATH is modified.

Author: cderv

setup/action.yml

@@ -99,12 +99,6 @@ runs:
                   exit 1
               fi
 
-              # Verify Quarto is available
-              if ! command -v quarto &> /dev/null; then
-                  echo "ERROR: Quarto installation completed but quarto command not found"
-                  exit 1
-              fi
-
               echo "Quarto Installed !"
               ;;
             *)