fix: update banner url missing release tag

[jukibom]

The update banner includes a clickable link which points to https://github.com/ebkr/r2modmanPlus/releases/tag/ which is a 404. It looks like a previous refactor here omitted the assignment of updateTagName which is supposed to be appended to the url in

<ExternalLink :url="`https://github.com/ebkr/r2modmanPlus/releases/tag/${updateTagName}`">

[ebkr]

I think we can actually just replace it entirely with a link to https://github.com/ebkr/r2modmanPlus/releases/latest

[jukibom]

I think we can actually just replace it entirely with a link to https://github.com/ebkr/r2modmanPlus/releases/latest

Oh yeah duh, that makes way more sense! Updated.

[CLAassistant]

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