Update dartdoc to use 0.24.1 (#23275)

dev/bots/docs.sh

diff --git a/dev/bots/docs.sh b/dev/bots/docs.sh
index 80481a8..7d09253 100755
--- a/dev/bots/docs.sh
+++ b/dev/bots/docs.sh
@@ -63,7 +63,7 @@
 fi
 
 # Install and activate dartdoc.
-"$PUB" global activate dartdoc 0.24.0
+"$PUB" global activate dartdoc 0.24.1
 
 # This script generates a unified doc set, and creates
 # a custom index.html, placing everything into dev/docs/doc.