Flaky tests: Increase shell timeout to allow for longer-running renderings

[ArchibaldBienetre]

I noticed a sometimes-failing (flaky) test on the main branch.

org.example.csv2tex.ErfurtSchoolReportSmokeTest
RenderingException{cause=SHELL_COMMAND_FAILED, additionalMessage='
ShellResult{
stdout=Optional[
This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019/Debian) (preloaded format=pdflatex) 
restricted \write18 enabled.
entering extended mode
LaTeX2e 
<2020-02-02> patch level 2L3 programming layer 
<2020-02-14>(/tmp/SchoolReportsRenderer17539504050464511336/schoolReport_0.tex(/tmp/SchoolReportsRenderer17539504050464511336/SchoolReportTemplate_ZeugnisTemplate_Packages.tex
[...]
Output written on schoolReport_0.pdf (3 pages, 87603 bytes).Transcript written on schoolReport_0.log.
], stderr=Optional[], exitCode=Optional.empty, successfulExit=false}'}

https://app.circleci.com/pipelines/github/SergelsOrg/csv2tex/285/workflows/918bc317-886e-4c7f-a0f5-d8e9976ef2f4/jobs/1153

What strikes the eye here is that there is no non-0 exit code - the command did not finish successfully.

Looking at the code, I found that we still hard-code a 1-second timeout to avoid hanging applications - this may be too low for real-life renderings of multiple pages.