Add comments for DinoV3 re global pool (class token). Fix #2681 #3029

Job	Run time
Run tests on ubuntu-latest with Python 3.10	52m 7s
Run tests on ubuntu-latest with Python 3.10	48m 13s
Run tests on ubuntu-latest with Python 3.10	1h 22m 3s
Run tests on ubuntu-latest with Python 3.13	39m 47s
Run tests on ubuntu-latest with Python 3.10	3m 2s
Run tests on ubuntu-latest with Python 3.13	29m 5s
Run tests on ubuntu-latest with Python 3.10	53m 52s
Run tests on ubuntu-latest with Python 3.10	1h 11m 49s
Run tests on ubuntu-latest with Python 3.10	2m 21s
Run tests on ubuntu-latest with Python 3.10	37m 22s
Run tests on ubuntu-latest with Python 3.10	31m 48s
Run tests on ubuntu-latest with Python 3.13	40m 20s
Run tests on ubuntu-latest with Python 3.10	35m 4s
Run tests on ubuntu-latest with Python 3.10	38m 27s
Run tests on ubuntu-latest with Python 3.13	1h 7m 51s
Run tests on ubuntu-latest with Python 3.13	2m 46s
Run tests on ubuntu-latest with Python 3.10	1h 37m 0s
Run tests on ubuntu-latest with Python 3.10	34m 32s
Run tests on ubuntu-latest with Python 3.13	56m 13s
Run tests on ubuntu-latest with Python 3.10	42m 36s
Run tests on ubuntu-latest with Python 3.13	31m 33s
	14h 57m 51s

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