Some (most?) of them looks to be unicode strings, and according to the very end of the main function:

#ifdef __INSURE__
    /* Insure++ is a memory analysis tool that aids in discovering
     * memory leaks and other memory problems.  On Python exit, the
     * interned string dictionaries are flagged as being in use at exit
     * (which it is).  Under normal circumstances, this is fine because
     * the memory will be automatically reclaimed by the system.  Under
     * memory debugging, it's a huge source of useless noise, so we
     * trade off slower shutdown for less distraction in the memory
     * reports.  -baw
     */
    _Py_ReleaseInternedUnicodeStrings();
#endif /* __INSURE__ */

So, to ensure everything is as expected, I compiled with the __INSURE__ flag, and got:

releasing 1894 interned strings
total size of all interned strings: 17945/0 mortal/immortal
ASAN:DEADLYSIGNAL
=================================================================
==23814==ERROR: AddressSanitizer: SEGV on unknown address 0x0000000000a0 (pc 0x5575b1c16904 bp 0x7ffe1c4f1f60 sp 0x7ffe1c4f1f40 T0)
    #0 0x5575b1c16903 in list_dealloc (/home/mdk/Downloads/cpython/python+0x524903)
    #1 0x5575b1bf287d in _Py_Dealloc (/home/mdk/Downloads/cpython/python+0x50087d)
    #2 0x5575b1c3daca in _Py_ReleaseInternedUnicodeStrings (/home/mdk/Downloads/cpython/python+0x54baca)
    #3 0x5575b206c0d3 in Py_Main (/home/mdk/Downloads/cpython/python+0x97a0d3)
    #4 0x5575b206d1d2 in main (/home/mdk/Downloads/cpython/python+0x97b1d2)
    #5 0x7f5ed0b622b0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202b0)
    #6 0x5575b1b1f8d9 in _start (/home/mdk/Downloads/cpython/python+0x42d8d9)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/home/mdk/Downloads/cpython/python+0x524903) in list_dealloc
==23814==ABORTING

Which in this case does not looks normal.