Add fresh NEWS entry for JSON encoder memory leak fix

Author: okiemute04

Misc/NEWS.d/next/Library/2026-03-19-04-18-27.gh-issue-146152.Ifrd7O.rst

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+Fix a memory leak in the :mod:`json` module when a RecursionError occurs
+during encoding. Previously, objects created in the `default()` function
+while recursively encoding JSON could remain alive due to being tracked
+indefinitely in the encoder's internal circular-reference dictionary. This
+change ensures such objects are properly freed after the exception.