Update links to the agama-weblate repository

[lslezak]

Problem

• The agama-weblate repository has been also moved

Solution

• Update the references in the GitHub Actions to use generic github.repository_owner (the actions use !github.event.repository.fork condition so they should never run outside of the project-agama , but this is more flexible)
• Update the links in the documentation

Notes

• I was thinking about using relative URLs in the documentation, but then it would not work in forks (unless you fork the agama-weblate repository as well). Absolute URLs are probably better here, I do not expect we move the location anytime soon. 😃

[imobachgs]

It is agama-project, not project-agama.