do not export unset fields, and set min python version (#15)

Author: mingness

.github/workflows/update_contributions.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v5
         with:
-          python-version: 3.x
+          python-version: '>=3.11'
 
       - name: Install dependencies
         run: pip install -r requirements.txt

scripts/parse_and_validate_properties_txt.py

@@ -101,19 +101,19 @@ def validate_existing(properties_dict):
     # validation on existing contribution is weaker
     properties = PropertiesExisting.model_validate(properties_dict)
 
-    return properties.model_dump()
+    return properties.model_dump(exclude_unset=True)
 
 def validate_new(properties_dict):
     # new contribution has stronger validation
     properties = PropertiesBase.model_validate(properties_dict)
 
-    return properties.model_dump()
+    return properties.model_dump(exclude_unset=True)
 
 def validate_new_library(properties_dict):
     # new contribution has stronger validation
     properties = LibraryPropertiesNew.model_validate(properties_dict)
 
-    return properties.model_dump()
+    return properties.model_dump(exclude_unset=True)
 
 def set_output(output_object):
     with open(os.environ['GITHUB_OUTPUT'],'a') as f: