package/python-sip: disable parallel install
{host-}python-sip may fail to install on fast machine, so disable
parallel install.
Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/8350440972 (TestPythonPyQt5)
http://autobuild.buildroot.org/results/8f2/8f24656f3a66d21f2d3c6d6b1adc6bb5f1c0c801 (2024-10-15)
http://autobuild.buildroot.org/results/6e6/6e6bbee714b10e0f04c9d17b7e0ecce057d21d2a (2022-07-15)
Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 4b271906a74ab773ff276cf5d6d90209c4d32cab)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
c1a393045f