stack/slapos: version up jsonschema 4.17.3 (on py3)

This brings support for 2020-12 schemas. The python2 version is
left unchanged

stack/slapos.cfg

@@ -203,7 +203,7 @@ itsdangerous = 0.24
 jdcal = 1.4
 jedi = 0.17.2
 Jinja2 = 2.11.3
-jsonschema = 3.0.2:whl
+jsonschema = 4.17.3:whl
 jupyter = 1.0.0
 jupyter-client = 7.3.1
 jupyter-console = 6.4.4
@@ -337,6 +337,7 @@ distro = 1.6.0
 feedparser = 5.2.1
 gitdb2 = 2.0.5
 GitPython = 2.1.11
+jsonschema = 3.0.2:whl
 pyparsing = 2.2.0
 pyrsistent = 0.16.1
 requests = 2.27.1