Upgrade singular to >= 4.4.1

[behackl]

As per my report on sage-release, in order to have sage build successfully with clang17 on new macs, the changes from Singular/Singular@d3f7343 need to be applied, either as a separate patch (as demonstrated here), or -- the probably better variant -- by upgrading singular to 4.4.1, released in January 2025.

[DaveWitteMorris]

I think we should close this because the upgrade was done in #40033.