build: Remove obsolete comment

.github/workflows/ci.yml

@@ -1,10 +1,3 @@
-# This file was automatically generated by mill-github-actions using the
-# githubWorkflowGenerate task. You should add and commit this file to
-# your git repository. It goes without saying that you shouldn't edit
-# this file by hand! Instead, if you wish to make changes, you should
-# change your mill build configuration to revise the workflow description
-# to meet your needs, then regenerate this file.
-
 name: Continuous Integration
 
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