moved pystac dependency from test to general Open-EO#527

setup.py

@@ -30,7 +30,6 @@
     "flake8>=5.0.0",
     "time_machine",
     "pyproj>=3.2.0",  # Pyproj is an optional, best-effort runtime dependency
-    "pystac"
 ]
 
 docs_require = [
@@ -74,6 +73,7 @@
         "numpy>=1.17.0",
         "xarray>=0.12.3",
         "pandas>0.20.0",
+        "pystac",
         "deprecated>=1.2.12",
         'oschmod>=0.3.12; sys_platform == "win32"',
         "importlib_resources; python_version<'3.9'",