editorconfig: special-case Python scripts

Python's PEP 8 specifies that one shall use spaces instead of tabs as
coding style, and we actually honor that currently. Our EditorConfig
does not special-case Python scripts, though, which is why we end up
with our C coding style and thus with tabs.

Special-case "*.py" files to override that default with spaces to fix
this.

.editorconfig

@@ -15,3 +15,7 @@ indent_size = 2
 indent_style = space
 indent_size = 4
 trim_trailing_whitespace = false
+
+[*.py]
+indent_style = space
+indent_size = 4