gh-145876: preserve AttributeError in dict unpacking #2355

Job	Run time
x86_64-unknown-linux-gnu/gcc	10m 16s
aarch64-apple-darwin/clang	9m 29s
x86_64-apple-darwin/clang	18m 13s
x86_64-pc-windows-msvc/msvc	9m 41s
x86_64-pc-windows-msvc/msvc-free-threading	5m 0s
aarch64-unknown-linux-gnu/gcc	7m 20s
x86_64-unknown-linux-gnu/gcc-free-threading	8m 36s
	1h 8m 35s

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