[clang] [clang][Python] Use fstrings instead of string concatenations (PR #173861)

[Jannick Kremer via cfe-commits]

DeinAlptraum wrote:

> In the future please refrain from rebasing the branch, because it makes it harder for reviewers to see history of the changes. Merge commits are not a problem, because PRs are squashed upon merging.

Which is exactly what Endilll asked you to do ;)

https://github.com/llvm/llvm-project/pull/173861