gh-38339: Add sage.misc.latex.pdf to save the image of objects to pdf
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Hence
```sage
sage: from sage.misc.latex import pdf
sage: pdf(pi, 'test.pdf')
```
works. This is a companion to the existing `sage.misc.latex.png`, which
saves png image of objects. Of course, pdf image is scalable and hence
more suitable for inclusion into latex documents.
Also we fix it that `view()` sporadically fails on mac because the
temporary file is removed before the viewer opens the file. For example,
```sage
sage: view(pi) # show pi
```
Thus after this PR, the temporary file is removed when the viewer
(`Preview` app on mac, not the window showing the image) closes. This
behavior is consistent with that on linux.
### :memo: Checklist
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- [ ] I have updated the documentation and checked the documentation
preview.
### :hourglass: Dependencies
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URL: https://github.com/sagemath/sage/pull/38339
Reported by: Kwankyu Lee
Reviewer(s): Dima Pasechnik
