Temporarily disable aarch64-apple-darwin JIT CI jobs

Author: brandtbucher

.github/workflows/jit.yml

@@ -79,10 +79,11 @@ jobs:
             architecture: x86_64
             runner: macos-13
             compiler: clang
-          - target: aarch64-apple-darwin/clang
-            architecture: aarch64
-            runner: macos-14
-            compiler: clang
+          # GH-126464: A recent change to either GHA or LLVM broke this job:
+          # - target: aarch64-apple-darwin/clang
+          #   architecture: aarch64
+          #   runner: macos-14
+          #   compiler: clang
           - target: x86_64-unknown-linux-gnu/gcc
             architecture: x86_64
             runner: ubuntu-22.04