#48in24: Sync circular-buffer

[mk-mxp]

• Run bin/configlet sync -u -e circular-buffer --yes --docs --filepaths --metadata --tests include (updates the Markdown files and maybe tests.toml)
• Drop strict types comments from test file and example code (these are useless)
• Add and sync test meta data to tests (uuid / @testdox in DocBlocks)
• Decide on adding / adjusting / ordering test cases to match current problem specs

Do not redesign the student's interface or add test cases that would invalidate existing community solutions. These are extra tasks, which should be discussed in advance.