Fix compatibility issues, drop Python 3.9, and pull Git LFS fiels handling

- Removed Python 3.9 from CI due to compatibility issues
- Fixed None values for element properties
- Added Git LFS pull instructions to GitHub workflows

Author: enjyashraf18

.gitattributes

@@ -0,0 +1 @@
+*.h5 filter=lfs diff=lfs merge=lfs -text

.github/workflows/pytest.yaml

@@ -18,25 +18,29 @@ jobs:
         # windows-latest is not supported because pyscf is not supported on windows
         # https://pyscf.org/user/install.html
         os: ["ubuntu-latest", "macos-latest"]
-        py: ["3.9", "3.10", "3.11", "3.12"]
+        py: ["3.10", "3.11", "3.12"]
 
     steps:
       - uses: "actions/checkout@v4"
+        # Whether to download Git-LFS files
+        with:
+          lfs: true
 
       - name: Setup python for test ${{ matrix.py }}
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.py }}
+          python-version: ${{ matrix.py }}      
 
       - name: Install development version
         run: |
-          pip install -v .
+          pip install -e .
 
       - name: Install extra test dependencies
         run: |
           pip install --upgrade pip
           pip install .[test_extra]
 
+
       - name: Run pytest default tests
         uses: pavelzw/pytest-action@v2
         with:
@@ -49,7 +53,7 @@ jobs:
       - name: Install Dev Dependencies
         run: |
           pip install .[dev]
-
+      
       - name: Run pytest Dev Tests
         uses: pavelzw/pytest-action@v2
         with:
@@ -59,3 +63,5 @@ jobs:
           click-to-expand: true
           report-title: 'Dev Test Report'
           pytest-args: '-m dev'
+
+

atomdb/data/database_beta_1.3.0.h5

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:af6bc5014271228a3f11c7b64e4dfc5b41a28193c77bd319d59ca8043f2aa4b9
+size 105117616