c46d8c0a1 Update README.md for consistency with framework (flutter/engine#9428) (#34910)

https://github.com/flutter/engine/compare/5153075e5fdf...c46d8c0a155a

git log 5153075e5fdfdbcdb2c7e9fae3743ca015c68773..c46d8c0a155a433344dc4e0b65b7a6a23b3ea81b --no-merges --oneline
c46d8c0a1 Update README.md for consistency with framework (flutter/engine#9428)

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bin/internal/engine.version

-5153075e5fdfdbcdb2c7e9fae3743ca015c68773
+c46d8c0a155a433344dc4e0b65b7a6a23b3ea81b