Add a set of asserts to test.test_capi.test_list

[nybblista]

Add a set of asserts to enhance test.test_capi.test_list test. For example, this test lacks some of the 0-sized tests for some cases, and there is room for other asserts.

Linked PRs

• gh-131441: Add a set of asserts to test.test_capi.test_list #131442
• [3.13] gh-131441: Add a set of asserts to test.test_capi.test_list (GH-131442) #131523
• [3.12] gh-131441: Add a set of asserts to test.test_capi.test_list (#131442) #131533

[nybblista]

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