Simplified test code

[radarhere]

Replace

f = str(tmp_path / "temp.png")

with

f = tmp_path / "temp.png"

where possible.

[hugovk]

I guess most of these are fine, but are any of these actually testing it works with a string?

[radarhere]

Almost all of these changes are about opening and saving. I've added an explicit test for opening and saving an image using a string.

An exception is a call to ImageFont.truetype(), but we already have other tests that pass strings to that -

Pillow/Tests/test_imagefont.py

Line 56 in e66ebb6

return ImageFont.truetype(FONT_PATH, FONT_SIZE, layout_engine=layout_engine)