Migrate to libyang2

Also update buildroot to latest master:
- the sdbus-cpp version bump patch has been removed, because upstream
  now bumped it to an even newer version

- Fix RAUC not able to start a service
(https://github.com/buildroot/buildroot/commit/72308ab9a32de6e8b4b23e42f115ed5ee87e5f33)

Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/netconf-cli/+/4539
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/netconf-cli/+/4539
Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/rousette/+/5391
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/rousette/+/5391
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/cla-sysrepo/+/5292
Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/velia/+/5237
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/velia/+/5237
Change-Id: I6edc19f35accfd41a4b32f7b396981d470e0c07b
diff --git a/.zuul.yaml b/.zuul.yaml
index af1a45e..4f65f1e 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -14,6 +14,8 @@
       - CzechLight/netconf-cli
       - CzechLight/velia
       - CzechLight/rousette
+      - CzechLight/libyang-cpp
+      - CzechLight/sysrepo-cpp
       - github/CESNET/libyang
       - github/sysrepo/sysrepo
       - github/CESNET/libnetconf2