Disable docs generation. (#24354)

Landing on red in order to fix the build.
diff --git a/dev/bots/docs.sh b/dev/bots/docs.sh
index 144a78c..eae672c 100755
--- a/dev/bots/docs.sh
+++ b/dev/bots/docs.sh
@@ -75,6 +75,9 @@
 # Ensure google webmaster tools can verify our site.
 cp "$FLUTTER_ROOT/dev/docs/google2ed1af765c529f57.html" "$FLUTTER_ROOT/dev/docs/doc"
 
+# TODO(gspencer): Re-enable this when Firebase hosting is fixed.
+exit 0
+
 # Upload new API docs when running on Cirrus
 if [[ -n "$CIRRUS_CI" && -z "$CIRRUS_PR" ]]; then
   echo "This is not a pull request; considering whether to upload docs... (branch=$CIRRUS_BRANCH)"