Don't assume footer is present in _ConsoleOutputState builder. (#9342)



---------

Co-authored-by: Nate Biggs <natebiggs@google.com>

packages/devtools_app/lib/src/shared/console/console.dart

diff --git a/packages/devtools_app/lib/src/shared/console/console.dart b/packages/devtools_app/lib/src/shared/console/console.dart
index ea3cc46..c9840ce 100644
--- a/packages/devtools_app/lib/src/shared/console/console.dart
+++ b/packages/devtools_app/lib/src/shared/console/console.dart
@@ -209,10 +209,11 @@
                 ),
               ),
               // consider constraining a max height.
-              Padding(
-                padding: const EdgeInsets.only(top: denseSpacing),
-                child: widget.footer!,
-              ),
+              if (widget.footer != null)
+                Padding(
+                  padding: const EdgeInsets.only(top: denseSpacing),
+                  child: widget.footer,
+                ),
             ],
           ),
         ),