Font Engine Layout Tables memory increases when repeatedly entering Play Mode with custom fonts used in a UIDocument

Reproduction steps:
1. Open the attached “BugFontTables.zip” project
2. Open the “Assets/Scenes/SampleScene.unity” scene
3. Open Window > Analysis > Memory Profiler
4. Press “Capture New Snapshot” (to capture a baseline snapshot)
5. Use an autoclicker or manually repeatedly click the Play button to enter and exit Play Mode for at least 5 minutes
6. In Memory Profiler, press “Capture New Snapshot”
7. Compare the snapshots in “All Of Memory” and inspect: Native > Unity Subsystems > Font Engine > Layout Tables
8. Observe Memory usage increase in later Snapshot

Actual result: Layout Tables memory allocation grows from ~0.43 GB to ~0.62 GB
Expected result: Memory allocation remains about the same

Reproducible with: 2023.1.0a1, 6000.0.73f1, 6000.3.13f1, 6000.4.3f1, 6000.5.0b5, 6000.6.0a2

Reproducible environment: Windows 11
Not reproducible environment: No other environments tested

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Related slack thread: https://unity.slack.com/archives/C5AURAWV7/p1776345973505719?thread_ts=1776345954.213669&cid=C5AURAWV7