In the master nightlies on Ubuntu 22.04, we see some warnings caused by civentweb:
https://lcgapp-services.cern.ch/root-jenkins/view/ROOT%20Nightly/job/root-nightly-master/LABEL=ROOT-ubuntu2204,SPEC=soversion,V=master/lastBuild/parsed_console/

warning: ‘SHA1_Init’ is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
12345 |         SHA1_Init(&sha_ctx);
warning: ‘SHA1_Update’ is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
warning: ‘SHA1_Final’ is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]

Usage of these deprecated functions has been removed in the civetweb master branch:
civetweb/civetweb#1072

Hence, once civetweb 1.16 is out, the code should by synchronized again with the ROOT repository to avoid these warnings.