editors/libreoffice: fix build with lld 17 (take 2)

Building editors/libreoffice with lld 17 results in the following link
errors:

ld: error: version script assignment of 'PRIVATE_1.4' to symbol '_ZN3sal13backtrace_getEm' failed: symbol not defined
ld: error: version script assignment of 'GLIBCXX_3.4' to symbol '_ZNSs4_Rep20_S_empty_rep_storageE' failed: symbol not defined

Add -Wl,--undefined-version to LDFLAGS to suppress these error, as the
previous fix did not work in all cases.

PR: 274697
Approved by: office (blanket)
Fixes: 6338934b7c42
MFH: 2024Q4