gh-35373: Fix workflow "Build documentation (PDF)"
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### :books: Description
Follow-up on #35169.
The container `sage-docker-fedora-31-maximal-with-targets` used for the
PDF docbuild turned out to be not reliable.
Here we replace it by `ubuntu-focal-standard-with-targets` and install
texlive in it.
We also copy over the incremental build from doc-build.yml and the
method to get CI fixes from blocker tickets from #36338.
This workflow is currently disabled in sagemath/sage.
Example run:
https://github.com/mkoeppe/sage/actions/runs/6318741659/job/17158468016
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### :hourglass: Dependencies
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- Depends on #36338
- Depends on #36348
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URL: https://github.com/sagemath/sage/pull/35373
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik
