As Jenszcz mentioned in his comment that you can solve this problem by using BartyCrouch open-source project, I was curios to give it a try And worked excellently :) Here are the steps I followed to get it work within 5 minutes.
1- Install BartyCrouch. See the installation procedure from url.
2- Created a sample project, which you can access here. In that project created 2 labels ("Text Included" & "Text Excluded #bc-ignore!").
3- Add RunScript (instructions on how to add a build script here)
if which bartycrouch > /dev/null; then
bartycrouch update -x
bartycrouch lint -x
else
echo "warning: BartyCrouch not installed, download it from https://github.com/Flinesoft/BartyCrouch"
fi
4- After building the project the Main.strings file excluded one label.Here are the screenshots showing the storyboard file & .strings file.