[Godot] Ignore imported translations (#3269)

The Godot editor automatically creates those binary files from
translations in CSV format. There's no need to add them to
version control.

Godot.gitignore

@@ -4,6 +4,9 @@
 export.cfg
 export_presets.cfg
 
+# Imported translations (automatically generated from CSV files)
+*.translation
+
 # Mono-specific ignores
 .mono/
 data_*/