[3.13] Explain how to install LLVM on Fedora (GH-119100)

(cherry picked from commit ab73bcd)
Co-authored-by: Miro Hrončok <miro@hroncok.cz>
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>

Author: miss-islington

Diff for: Tools/jit/README.md

@@ -21,6 +21,12 @@ chmod +x llvm.sh
 sudo ./llvm.sh 18
 ```
 
+Install LLVM 18 on Fedora Linux 40 or newer:
+
+```sh
+sudo dnf install 'clang(major) = 18' 'llvm(major) = 18'
+```
+
 ### macOS
 
 Install LLVM 18 with [Homebrew](https://brew.sh):