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Bump default language edition to GHC2024
Per [this accepted ghc-proposal](https://github.com/ghc-proposals/ghc-proposals/pull/632) we should bump GHC's default language edition to `GHC2024` (see [implementation plan here](https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0613-ghc2024.rst#implementation-plan)). In the future, newly introduced language editions are expected to become the default immediately. See #26037 and #26038 for related changes that should reduce the potential stability impact of this change.
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