Fix OWLv2 Doc

[jla524]

What does this PR do?

Fixes #30686 (comment)

Tested on a 7900 XTX machine

% pytest --doctest-modules docs/source/en/model_doc/owlv2.md -sv --doctest-continue-on-failure --doctest-glob="*.md"
<log redacted>
=========================================================== test session starts ============================================================
platform linux -- Python 3.10.12, pytest-7.4.4, pluggy-1.5.0 -- /home/jacky/repos/transformers/env/bin/python3
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase(PosixPath('/home/jacky/repos/transformers/.hypothesis/examples'))
rootdir: /home/jacky/repos/transformers
configfile: pyproject.toml
plugins: timeout-2.3.1, hydra-core-1.3.2, hypothesis-6.102.1, rich-0.1.1, xdist-3.6.1, dash-2.17.0, anyio-4.3.0
collected 1 item                                                                                                                           

docs/source/en/model_doc/owlv2.md::owlv2.md PASSED

<warnings redacted>
====================================================== 1 passed, 2 warnings in 4.26s =======================================================

Who can review?

@ydshieh @amyeroberts

[ydshieh]

Our T4 runners gives the same new value. Thank you for the quick fix @jla524 !