This bug fix release address issues found in the new string interpolation feature

• Add (*TemplateString).Copy() method (#8159) authored by @anderseknert
• Fix template string not serialized with escaped { (#8161) authored by @anderseknert
• fix(ast): skip template string vars in ref safety (#8174) authored by @thevilledev
• fix(ast): use original var names in template error (#8180) authored by @thevilledev