mention Coq 8.11 in changelog

5 jobs for master in 16 minutes and 21 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
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build-coq.8.10.2

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build-coq.8.11.0

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build-coq.8.8.2

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build-coq.8.9.1

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build-coq.dev

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