[red-knot] Add a regression test for recent improvement to `TypeInfer… #234

Job	Run time
cargo fmt	21s
Determine changes	11s
cargo build (release)	5m 26s
mkdocs	2m 27s
pre-commit	3m 24s
python package	1m 33s
cargo clippy	1m 57s
cargo test (linux)	1s
cargo fuzz build	4m 34s
cargo build (msrv)	1s
cargo shear	21s
cargo test (linux, release)	1s
cargo test (wasm)	1m 45s
cargo test (windows)	1s
formatter instabilities and black similarity	3m 21s
test scripts	1m 4s
benchmarks	0s
fuzz parser	0s
test ruff-lsp	0s
ecosystem	0s
	26m 28s

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