fix: load .NET assemblies when running on .NET 9+

GitHub-hosted runners now ship .NET 8, 9 and 10. clr_loader 0.2.x (used
with pythonnet 3.0.x, e.g. on Python 3.9) picks the runtime by string
sort, so it selects .NET 9. On .NET 9+, pythonnet 3.0.x's
clr.AddReference("<abs path>.dll") parses the path as an assembly name
and throws FileNotFoundException before its full-path fallback runs. The
error was swallowed, so imports failed with
"No module named 'Microsoft.Azure'".

Pass the path without the ".dll" suffix so pythonnet probes and loads
"<path>.dll" directly, which works on .NET 8, 9 and 10 with pythonnet
3.0.x and 3.1.x.

Also pin the e2e matrix to Python 3.13 instead of '3.x', which now
resolves to 3.14 and is outside requires-python (<3.14).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: arjenkroezen-msft

.github/workflows/ci.yml

@@ -88,7 +88,7 @@ jobs:
     strategy:
       matrix:
         os: ['ubuntu-latest', 'windows-latest']
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.x']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
         dotnet-version: ['8.0.x']
         dist: [whl, sdist]
     uses: ./.github/workflows/e2e.yml

src/data_factory_testing_framework/_pythonnet/__init__.py

@@ -10,9 +10,11 @@
 def load_dotnet_assemblies() -> None:
     # Load the .NET assemblies
     for dll in (Path(__file__).parent / "bin").glob("**/*.dll"):
-        dll = os.path.abspath(dll)
+        # Pass the path without the ".dll" suffix so pythonnet probes and loads "<path>.dll" directly.
+        # With the suffix, pythonnet 3.0.x on .NET 9+ parses the path as an assembly name and fails to load it.
+        assembly_path = os.path.splitext(os.path.abspath(dll))[0]
         try:
-            clr.AddReference(dll)
+            clr.AddReference(assembly_path)
         except Exception:
             pass