Update xproperty to 0.12.0 (emscripten-forge#1084)

* Update xproperty to 0.12.0

* Added tests

recipes/recipes_emscripten/xproperty/recipe.yaml

@@ -1,32 +1,36 @@
 context:
-  version: 0.11.0
+  version: 0.12.0
 
 package:
   name: xproperty
   version: ${{ version }}
 
 source:
   url: https://github.com/jupyter-xeus/xproperty/archive/refs/tags/${{ version }}.tar.gz
-  sha256: bf86a11c6758308aa0aa0f64d8dd24cd3e9d78378467b74002f552bfb75fc0eb
+  sha256: 27cbc8e441dcc515a1ebbf11bad5ef240748d32f5e1adf84deed87a1dc57a440
 
 build:
-  number: 2
+  number: 0
 
 requirements:
   build:
   - ${{ compiler("cxx") }}
   - cmake
   - ninja
   host:
-  - xtl >=0.7,<0.8
+  - nlohmann_json >=3.11.2
   run:
-  - xtl >=0.7,<0.8
+  - nlohmann_json >=3.11.2
+
+tests:
+- script:
+    - test -f $PREFIX/include/xproperty/xproperty.hpp
 
 about:
   license: BSD-3-Clause
   license_family: BSD-3
   license_file: LICENSE
-  summary: xtl
+  summary: Traitlets-like C++ properties and implementation of the observer pattern
   homepage: https://github.com/jupyter-xeus/xproperty
 extra:
   recipe-maintainers: