purpose of GnuTLS versions

[Jack Hill]

Hi Guix,

We currently have two versions of GnuTLS packaged: 3.7.2 represented by 
the `gnutls` variable and 3.7.7 represented by the `gnutls-latest` 
variable. `guix refresh -l` reports that changes to the 3.7.2 version 
would cause 14770 rebuilds, but only 30 rebuilds for the 3.7.7 version. As 
far as I can tell, neither version currently has a replacement (graft).

What is the purpose of these two versions? 3.7.7 is almost the current 
release [0], but 3.7.2 is an older release in the same series. GnuTLS does 
have two release series [1], stable and next, that correspond to 3.6.x and 
3.7.x numbering schemes.

It seems to me that the `gnutls` variable should refer to the latest 
"stable" release, and the `gnutls-latest` variable to latest "next" 
release. Does that make sense? What am I missing?

It appears that 3.7.2 has some unpatched advisories [2].

[0] https://issues.guix.gnu.org/61064
[1] https://gitlab.com/gnutls/gnutls/-/blob/master/RELEASES.md
[2] https://gnutls.org/security-new.html

Best,
Jack