'libei:sigalrm / eierpecken' test timeout on some systems

The 1.2.0-1 version failed to build on amd64 and i386 in Debian on similar timeout errors (1.1.0 didn't hit that issue).

Build log example on https://buildd.debian.org/status/fetch.php?pkg=libei&arch=i386&ver=1.2.0-1&stamp=1701901975&raw=0

command:      UBSAN_OPTIONS=halt_on_error=1:abort_on_error=1:print_summary=1:print_stacktrace=1 MALLOC_PERTURB_=52 ASAN_OPTIONS=halt_on_error=1:abort_on_error=1:print_summary=1 LD_LIBRARY_PATH=/<<PKGBUILDDIR>>/obj-i686-linux-gnu/src:/<<PKGBUILDDIR>>/obj-i686-linux-gnu/subprojects/munit /<<PKGBUILDDIR>>/obj-i686-linux-gnu/test/eierpecken --log-visible debug --enable-sigalarm
----------------------------------- stdout -----------------------------------
Running test suite with seed 0x03585bc1...
test_passive_ei_flush_frame          
==============================================================================

The same package built fine on Ubuntu amd64 but is failing on the ppc64el builders reliably, it seems it might be racy and depending of the machine rather than of the architecture.

I've no be able to reproduce the issue building locally or on a porter machine which makes it difficult to get more debugging information...