Tests fail with Pillow 8.3.1

[QuLogic]

Describe the bug
I believe this upgrade from Pillow 8.2.0 to 8.3.1 caused two new failures:

____________________________ test_rasterize_rotated ____________________________
[gw3] linux -- Python 3.10.0 /usr/bin/python3
francais = (PosixPath('/builddir/build/BUILD/ocrmypdf-12.2.0/tests/resources/francais.pdf'), <pikepdf.Pdf description='/builddir/build/BUILD/ocrmypdf-12.2.0/tests/resources/francais.pdf'>)
outdir = PosixPath('/tmp/pytest-of-mockbuild/pytest-0/popen-gw3/test_rasterize_rotated0')
caplog = <_pytest.logging.LogCaptureFixture object at 0x7fff7b598130>
    def test_rasterize_rotated(francais, outdir, caplog):
        path, pdf = francais
        page_size_pts = (pdf.pages[0].MediaBox[2], pdf.pages[0].MediaBox[3])
        assert pdf.pages[0].MediaBox[0] == pdf.pages[0].MediaBox[1] == 0
        page_size = (page_size_pts[0] / Decimal(72), page_size_pts[1] / Decimal(72))
        target_size = Decimal('50.0'), Decimal('30.0')
        forced_dpi = Resolution(42.0, 4242.0)
    
        caplog.set_level(logging.DEBUG)
        rasterize_pdf(
            path,
            outdir / 'out.png',
            raster_device='pngmono',
            raster_dpi=Resolution(
                target_size[0] / page_size[0], target_size[1] / page_size[1]
            ),
            page_dpi=forced_dpi,
            rotation=90,
        )
    
        with Image.open(outdir / 'out.png') as im:
            assert im.size == (target_size[1], target_size[0])
>           assert im.info['dpi'] == (forced_dpi[1], forced_dpi[0])
E           assert (4242.0032, 42.0116) == (4242.0, 42.0)
E             At index 0 diff: 4242.0032 != 4242.0
E             Use -v to get the full diff
tests/test_ghostscript.py:75: AssertionError
------------------------------ Captured log call -------------------------------
DEBUG    ocrmypdf.subprocess:__init__.py:112 Running: ['gs', '-dQUIET', '-dSAFER', '-dBATCH', '-dNOPAUSE', '-sDEVICE=pngmono', '-dFirstPage=1', '-dLastPage=1', '-r16.666667x10.000000', '-o', '-', '-sstdout=%stderr', '-dAutoRotatePages=/None', '-f', '/builddir/build/BUILD/ocrmypdf-12.2.0/tests/resources/francais.pdf']
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'IHDR' 16 13
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'iCCP' 41 2296
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:391 iCCP profile name b'default_gray.icc'
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:392 Compression method 0
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'pHYs' 2349 9
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'tEXt' 2370 31
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'IDAT' 2413 63
DEBUG    ocrmypdf._exec.ghostscript:ghostscript.py:126 Rotating output by 90
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'IHDR' 16 13
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'iCCP' 41 2291
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:391 iCCP profile name b'ICC Profile'
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:392 Compression method 0
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'pHYs' 2344 9
DEBUG    PIL.PngImagePlugin:PngImagePlugin.py:186 STREAM b'IDAT' 2365 106
_____________________________ test_rasterize_size ______________________________
[gw0] linux -- Python 3.10.0 /usr/bin/python3
francais = (PosixPath('/builddir/build/BUILD/ocrmypdf-12.2.0/tests/resources/francais.pdf'), <pikepdf.Pdf description='/builddir/build/BUILD/ocrmypdf-12.2.0/tests/resources/francais.pdf'>)
outdir = PosixPath('/tmp/pytest-of-mockbuild/pytest-0/popen-gw0/test_rasterize_size0')
    def test_rasterize_size(francais, outdir):
        path, pdf = francais
        page_size_pts = (pdf.pages[0].MediaBox[2], pdf.pages[0].MediaBox[3])
        assert pdf.pages[0].MediaBox[0] == pdf.pages[0].MediaBox[1] == 0
        page_size = (page_size_pts[0] / Decimal(72), page_size_pts[1] / Decimal(72))
        target_size = Decimal('50.0'), Decimal('30.0')
        forced_dpi = Resolution(42.0, 4242.0)
    
        rasterize_pdf(
            path,
            outdir / 'out.png',
            raster_device='pngmono',
            raster_dpi=Resolution(
                target_size[0] / page_size[0], target_size[1] / page_size[1]
            ),
            page_dpi=forced_dpi,
        )
    
        with Image.open(outdir / 'out.png') as im:
            assert im.size == target_size
>           assert im.info['dpi'] == forced_dpi
E           assert (42.0116, 4242.0032) == Resolution(42.0x4242.0 dpi)
E             At index 0 diff: 42.0116 != 42.0
E             Use -v to get the full diff
tests/test_ghostscript.py:50: AssertionError

To Reproduce
/usr/bin/pytest -ra -n auto --runslow

Expected behavior
Tests pass

System (please complete the following information):

• OS: Fedora Rawhide (35)
• Python version: 3.10.0b3
• OCRmyPDF version: 12.2.0

Installation
Building from source