[clang] [polly] [clang-format] Revert breaking stream operators to previous default (PR #89016)

[via llvm-commits]

llvmbot wrote:

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Failed to cherry-pick: 29ecd6d50f14

https://github.com/llvm/llvm-project/actions/runs/8756865337

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/89016