Fix comment because I am bad at saving

Author: tmandry

src/ci/docker/host-x86_64/x86_64-gnu-integration/Dockerfile

@@ -1,5 +1,5 @@
-# This job builds Fuchsia. See docs at XXX TODO and the build-fuchsia.sh script
-# in this directory for more details.
+# This job builds Fuchsia. See the build-fuchsia.sh script in this directory for
+# more details.
 
 FROM ubuntu:22.04