UltimateBasic 1.6.7

What's Changed

• Fix debugger source lines when subs come before the main program by @zstarczali in #68
• Add palette statement for Ultimate 64 / C64U colour palette by @zstarczali in #69
• ci: add manual workflow to publish packages to FTP by @zstarczali in #70
• ci: add optional GitHub release step to package workflow by @zstarczali in #71

Full Changelog: 1.6.6...1.6.7