In some recent PRs, I've been getting the following in pre-merge runs:

   Woah! You appear to be trying to run flutter as root.
   We strongly recommend running the flutter tool without superuser privileges.

This is causing some tests to fail, and I'm not sure why and when this started happening.

PR with this problem and test failure (only changes some typos in the docs): #78755
Example test failure: https://cirrus-ci.com/task/4610742352609280?command=main#L4

cc/ @fkorotkov