src/sage/doctest/control.py: double the default test timeout
When running the test suite on an older machine, many files time
out. For example,
$ sage -t src/sage/manifolds/differentiable/tensorfield.py
...
File "src/sage/manifolds/differentiable/tensorfield.py", line 248,
in sage.manifolds.differentiable.tensorfield.TensorField
Warning: Consider using a block-scoped tag by inserting the line
'sage: # long time' just before this line to avoid repeating the
tag 4 times
s = t(a.restrict(U), b) ; s # long time
Timed out (and interrupt failed)
...
----------------------------------------------------------------------
Total time for all tests: 360.3 seconds
cpu time: 0.0 seconds
cumulative wall time: 0.0 seconds
This has run over the default (non-long) test timeout of 300s. This
commit doubles that default, a change that should be unobjectionable
for a few reasons:
1. This timeout is a last line of defense intended to keep the test
suite from looping forever when run unattended. For that purpose,
ten minutes is as good as five.
2. As more tests get added to each file, those files take longer to
test on the same hardware. It should therefore be expected that
we will sometimes need to increase the timeout. (Basically, if
anyone is hitting it, it's too low.)
3. We now use Github CI instead of patchbots for most automated
testing, and Github has its own timeout.
4. There is a separate mechanism, --warn-long, intended to catch
tests that run for too long. The test timeout should not be
thought of as a solution to that problem.
Closes: https://github.com/sagemath/sage/issues/32973
