[PATCH for-4.21] cirrus-ci: add json-c for libxl dependency

[Roger Pau Monne]

Add json-c package for libxl usage.  At the same time drop YAJL.

Signed-off-by: Roger Pau Monné <roger....@citrix.com>
---
Would be nice to have for 4.21, so that we test with json-c instead of
YAJL.  I plan to switch the FreeBSD Xen port use json-c for 4.21.

All seems fine:

https://cirrus-ci.com/build/5366905441091584
---
 .cirrus.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.cirrus.yml b/.cirrus.yml
index 7df7ff552222..0de1012d8c60 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -50,7 +50,7 @@ task:
 
   install_script: pkg install -y seabios gmake ninja bash
                                  pkgconf bison perl5
-                                 yajl lzo2 pixman argp-standalone
+                                 json-c lzo2 pixman argp-standalone
                                  libxml2 glib git python3 libinotify
 
   configure_script:
-- 
2.51.0