Enforce \n eol for Python writes

• Ensure utf-8 encoding if previously unspecified

misc/scripts/dotnet_format.py

@@ -10,7 +10,7 @@ for path in [
     "modules/mono/SdkPackageVersions.props",
 ]:
     os.makedirs(os.path.dirname(path), exist_ok=True)
-    with open(path, "w") as f:
+    with open(path, "w", encoding="utf-8", newline="\n") as f:
         f.write("<Project />")
 
 # Avoid importing GeneratedIncludes.props.