Use innosetup Github action over choco install

[krzywon]

With windows-latest recently moving to windows-2025, inno setup is no longer natively available. This was fixed in #3606, but one suggestion in the PR was to use a github action that installs it rather than using choco install. I merged the PR to try and get our builds working again, but is not the best long-term solution.

[llimeht]

If the action were an official action from the developers of innosetup or from github itself then this would be a definite win. When it's not and it also just runs choco install innosetup, it's less compelling.