JIT

GH-140479: Update JIT builds to use LLVM 21 #4334

Job	Run time
Interpreter (Debug)	10m 8s
Free-Threaded (Debug) (21)	16m 53s
JIT without optimizations (Debug) (21)	10m 52s
JIT with tail calling interpreter (21)	3m 30s
i686-pc-windows-msvc/msvc (Release)	12m 7s
x86_64-pc-windows-msvc/msvc (Debug)	18m 58s
aarch64-pc-windows-msvc/msvc (Release)	19m 23s
x86_64-apple-darwin/clang (Debug)	30m 46s
x86_64-apple-darwin/clang (Release)	20m 1s
aarch64-pc-windows-msvc/msvc (Debug)	23m 39s
aarch64-unknown-linux-gnu/gcc (Release)	5m 27s
i686-pc-windows-msvc/msvc (Debug)	23m 24s
x86_64-unknown-linux-gnu/gcc (Debug)	10m 55s
aarch64-apple-darwin/clang (Release)	11m 17s
x86_64-unknown-linux-gnu/gcc (Release)	6m 58s
aarch64-unknown-linux-gnu/gcc (Debug)	7m 19s
aarch64-apple-darwin/clang (Debug)	15m 55s
x86_64-pc-windows-msvc/msvc (Release)	11m 58s
	4h 19m 30s

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