PAC and BTI are two branch protection technique for aarch64 not unlike what CET is on Intel.
Upstream GnuTLS has https://gitlab.com/gnutls/gnutls/-/merge_requests/1843,
yet gnutls-3.8.8-1.el10 /usr/lib64/libgnutls.so.30
does not have "Properties: AArch64 feature: BTI, PAC" in the readelf -n output
(the rest of the binaries/libraries do),
suggesting that more work is needed to bring this feature into RHEL.