Migrate to libyang2

libnetconf2: getSchema and getConfig were no longer used in netconf-cli,
so I deleted them. They can get readded once the bindings get split into
a separate project.

sysrepo_access: Some sr_val stuff was removed.

YangSchema: type descriptions are not available
            availableNodes returns only input nodes for RPC nodes
            impl_getSchemaNode: no longer disables error printing

libyang: No longer supports leafrefs without the leaf it points to.

Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/dependencies/+/5171
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/dependencies/+/5171
Change-Id: Ie49381a003a61a7bb028be7b2fa1d9d926ac4e58
diff --git a/ci/pre.yaml b/ci/pre.yaml
new file mode 100644
index 0000000..4c71e88
--- /dev/null
+++ b/ci/pre.yaml
@@ -0,0 +1,7 @@
+- hosts: all
+  tasks:
+    - name: install pcre2
+      package:
+        name: pcre2-devel
+        state: present
+      become: true