gh-116296: Fix refleak in reduce_newobj() corner case #104896

Job	Run time
Check for source changes	11s
Check if generated files are up to date	5m 6s
Address sanitizer	6m 54s
Ubuntu SSL tests with OpenSSL (1.1.1w)	1m 58s
CIFuzz (address)	19m 27s
Ubuntu SSL tests with OpenSSL (3.0.13)	2m 1s
CIFuzz (undefined)	20m 51s
Ubuntu SSL tests with OpenSSL (3.1.5)	2m 2s
CIFuzz (memory)	22m 49s
Ubuntu SSL tests with OpenSSL (3.2.1)	2m 8s
Hypothesis tests on Ubuntu	4m 17s
macOS / build and test (macos-14)	8m 9s
macOS / build and test (macos-13)	8m 32s
macOS (free-threading) / build and test (macos-14)	9m 46s
Ubuntu / build and test	6m 38s
macOS (free-threading) / build and test (macos-13)	14m 44s
Ubuntu (free-threading) / build and test	7m 52s
Windows / build and test (x64)	14m 3s
Windows / build and test (x86)	13m 33s
Windows / build (arm64)	2m 41s
Windows (free-threading) / build (arm64)	2m 39s
Windows (free-threading) / build and test (x64)	23m 57s
Windows (free-threading) / build and test (x86)	25m 1s
Docs / Docs	2m 2s
Docs / Docs (Oldest Sphinx)	1m 40s
Docs / Doctest	5m 52s
All required checks pass	2s
	3h 54m 55s

Provide feedback