JIT

GH-136895: Update JIT builds to use LLVM 20 #4173

Job	Run time
Interpreter (Debug)	9m 53s
JIT without optimizations (Debug) (20)	11m 17s
Free-Threaded (Debug) (20)	16m 56s
i686-pc-windows-msvc/msvc (Release)	12m 4s
i686-pc-windows-msvc/msvc (Debug)	21m 44s
aarch64-pc-windows-msvc/msvc (Debug)	23m 55s
aarch64-pc-windows-msvc/msvc (Release)	16m 50s
x86_64-pc-windows-msvc/msvc (Release)	11m 36s
x86_64-pc-windows-msvc/msvc (Debug)	20m 34s
aarch64-apple-darwin/clang (Release)	9m 36s
x86_64-apple-darwin/clang (Debug)	25m 2s
x86_64-unknown-linux-gnu/gcc (Debug)	12m 58s
aarch64-apple-darwin/clang (Debug)	10m 35s
x86_64-unknown-linux-gnu/gcc (Release)	8m 21s
x86_64-apple-darwin/clang (Release)	16m 28s
aarch64-unknown-linux-gnu/gcc (Debug)	6m 54s
aarch64-unknown-linux-gnu/gcc (Release)	5m 55s
	4h 0m 38s

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