pin xarray to a stable version for pycalibration

setup.py

@@ -60,6 +60,7 @@ install_requires = [
         "astcheck==0.2.5",
         "astsearch==0.2.0",
         "cfelpyutils==1.0.1",
+        "calibration_client==10.0.0",
         "dill==0.3.0",
         "docutils==0.17.1",
         "dynaconf==3.1.4",
@@ -102,7 +103,7 @@ install_requires = [
         "sphinx==1.8.5",
         "tabulate==0.8.6",
         "traitlets==4.3.3",
-        "calibration_client==10.0.0",
+	"xarray==2022.3.0",
 ]
 
 if "readthedocs.org" not in sys.executable: