Replace ci-linux-incremental by ci-linux

[tobiasdiez]

The incremental runs are supposed to test package updates - however, exactly in those situations, they are not working since the rebuilt sagelib is not linking correctly against the new versions. For example, in the flint update #40259, we get

[sagemath_doc_html-none] [spkg-install] from sage.rings import complex_interval, integer
[sagemath_doc_html-none] [spkg-install] ImportError: libflint.so.20: cannot open shared object file: No such file or directory

https://github.com/sagemath/sage/actions/runs/15979364834/job/45070073007?pr=40259#step:11:4686

For this reason, the incremental runs are replaced here by the build-from-zero runs. Those are a bit slower but more reliable.

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.

⌛ Dependencies

[dimpase]

a package update might require rebuilding of its consumers. Doesn't meson deal with it automatically?

a build from "zero" is an overkill.

[tobiasdiez]

I think meson is not able to this either: #40307. But maybe it does work if you reconfigure meson.

[user202729]

Not quite. These failures correctly reveals failures to correctly track dependency version and rebuild corresponding files.

If we stop testing this, we're theoretically telling the user "if you git pull and the build fails, wipe the build directory and rebuild everything again is the only supported solution".

… which is what we are practically telling the user anyway (since so far nobody has time to fix the dependency tracking, e.g. not @vbraun in this specific linked pull request, or in a previous case, the libsingular 4.4.1 pull request)

Just to double check, test-long on each pull request still build incrementally right? (you may want to open a pull request on your repository and check test-long takes reasonable time)