glibc updarte 2.31 to 2.38

Hi,

we have SLES 15.5 which has glibc 2.31. Our admin told us that he's about to install the SLES 15.6 update which
containsglibc 2.38. 

I have built our PostgreSQL software from source on SLES 15.5, because we have some special requirements which the
packagescannot fulfill. So I have questions: 

1) Do I have to build it again on 15.6?

2) Does the glibc update have any impact? I recall having to have everything reindexed when the 2.28 update came due to
majorlocale changes, but I didn't have to do it since then. 

3) Where and how can I find out if it is necessary to reindex? And how can I find out what indexes would be affected.

I'd really appreciate your comments. Thanks very much in advance.

Paul