Skip console confirmation if ctanupload is set true in config.lua

[muzimuzhi]

Currently, when using l3build upload to upload a package to CTAN, console confirmation is mandatory hence not skippable. This prohibits scripts from uploading to CTAN automatically. This feature, though dangerous and perhaps not recommended, is requested by pgf workflow main.yml.

Since ctanupload has partially exposed to config.lua (partially because not documented yet), I suggest to skip console confirmation if ctanupload is set true, if you decide to allow automatic uploading.

l3build/l3build-upload.lua

Lines 73 to 79 in 51151c5

	if options["dry-run"] then
	ctanupload = false
	end
	-- if ctanupload is nil or false, only validation is attempted
	-- if ctanupload is true the ctan upload URL will be used after validation
	-- if upload is anything else, the user will be prompted whether to upload.
	-- For now, this is undocumented. I think I would prefer to keep it always set to ask for the time being.