Enhancement: Upgrade to libyang3

[bradh352]

Is it platform specific

generic

Importance or Severity

High

Description of the enhancement

SONiC currently uses 3 versions of libyang: 1.0.73, 1.0.184, and 2.1.148. All are end of life and potentially have security issues. The current release is 3.12.2 and that is what we are targeting here.

There are also numerous libyang related bugs that have been "worked around" in SONiC due to the shortcomings of libyang1. Hopefully upgrading to a modern version will resolve such issues.

Current Behavior

3 libyang versions

Proposed Behavior

single libyang version

PR Tracking Table

PR	description	dependencies
#21679	Remove libyang 1.0.184. build libyang 3.12.2, libyang-python 3.1.0. Migrate FRR to libyang 3. Update sonic-yang-models test cases specifically to make it easier to see libyang3-specific changes once those land. THIS CAN BE MERGED WITHOUT ANY POSSIBLE IMPACT	None
#21719	Port sonic-yang-models test cases THIS CAN BE MERGED WITHOUT ANY POSSIBLE IMPACT	#21679
#21716	Port sonic-yang-mgmt.	#21679, #21719
#21718	Update all subprojects that use libyang1 to depend on libyang3	#21679, #21719, #21716
sonic-net/sonic-utilities#3766	sonic-utilities	#21679, #21719, #21716, #21718
#21752, sonic-net/sonic-swss-common#973	swss-common	#21679, #21719, #21716, #21718
#21789, sonic-net/sonic-mgmt-common#157	sonic-mgmt-common (GOlang)	#21679, #21718
sonic-net/sonic-platform-daemons#589 , sonic-net/sonic-swss#3518 , sonic-net/sonic-dbsyncd#74 , sonic-net/sonic-restapi#157 , sonic-net/sonic-snmpagent#348 , sonic-net/sonic-platform-common#544	azure pipelines: update various external repos to pull in the libyang3 debs that are otherwise not in need of modification	all of the above
#21790	cleanup / remove libyang1	all of the above