To allow Github to display tra files with non-UTF-8 encoding correctly, you need to specify their encoding explicitly in .gitattributes
file.
It's optional and is not related to action in any way.
An example:
# Classic
mymod/tra/czech/**.tra working-tree-encoding=cp1250
mymod/tra/french/**.tra working-tree-encoding=cp1252
mymod/tra/german/**.tra working-tree-encoding=cp1252
mymod/tra/hungarian/**.tra working-tree-encoding=cp1250
mymod/tra/italian/**.tra working-tree-encoding=cp1252
mymod/tra/korean/**.tra working-tree-encoding=cp949
mymod/tra/polish/**.tra working-tree-encoding=cp1250
mymod/tra/portuguese/**.tra working-tree-encoding=cp1252
mymod/tra/russian/**.tra working-tree-encoding=cp1251
mymod/tra/spanish/**.tra working-tree-encoding=cp1252
mymod/tra/swedish/**.tra working-tree-encoding=cp1252
mymod/tra/schinese/**.tra working-tree-encoding=cp936
mymod/tra/tchinese/**.tra working-tree-encoding=cp950
mymod/tra/ukrainian/**.tra working-tree-encoding=cp1251
mymod/tra/vietnamese/**.tra working-tree-encoding=cp1258
# Classic or EE console, RU/UA
mymod/**/russian/**/install.tra working-tree-encoding=cp866
mymod/**/russian/**/setup.tra working-tree-encoding=cp866
mymod/**/ukrainian/**/install.tra working-tree-encoding=cp866
mymod/**/ukrainian/**/setup.tra working-tree-encoding=cp866
# EE only
mymod/tra/**/ee.tra working-tree-encoding=utf8
mymod/tra/**/*_ee.tra working-tree-encoding=utf8
# Linux console
mymod/**/setup-unix.tra working-tree-encoding=utf8
mymod/**/setup-osx.tra working-tree-encoding=utf8
# Windows console, other languages
mymod/tra_ee/czech/*-win32.tra working-tree-encoding=cp1250
mymod/tra_ee/french/*-win32.tra working-tree-encoding=cp1252
mymod/tra_ee/german/*-win32.tra working-tree-encoding=cp1252
mymod/tra_ee/hungarian/*-win32.tra working-tree-encoding=cp1250
mymod/tra_ee/italian/*-win32.tra working-tree-encoding=cp1252
mymod/tra_ee/korean/*-win32.tra working-tree-encoding=cp949
mymod/tra_ee/polish/*-win32.tra working-tree-encoding=cp1250
mymod/tra_ee/portuguese/*-win32.tra working-tree-encoding=cp1252
mymod/tra_ee/russian/*-win32.tra working-tree-encoding=cp866
mymod/tra_ee/spanish/*-win32.tra working-tree-encoding=cp1252
mymod/tra_ee/swedish/*-win32.tra working-tree-encoding=cp1252
mymod/tra_ee/schinese/*-win32.tra working-tree-encoding=cp936
mymod/tra_ee/tchinese/*-win32.tra working-tree-encoding=cp950
mymod/tra_ee/ukrainian/*-win32.tra working-tree-encoding=cp866
mymod/tra_ee/vietnamese/*-win32.tra working-tree-encoding=cp1258
After the file is created, tell git to re-read existing files:
git add --renormalize .
git commit -m "renormalize tras"