[v632] meta: Prevent memory hoarding for GetClass("int")

[pcanal]

or any other numerical types.

Backport of #18537

[github-actions]

Test Results

     9 files       9 suites   2d 8h 14m 56s ⏱️
 2 639 tests  2 639 ✅ 0 💤 0 ❌
22 172 runs  22 172 ✅ 0 💤 0 ❌

Results for commit fb68b97.