feat(bucket): Switch nirsoft bucket to ScoopInstaller/Nirsoft

[rasa]

Per #5293

• I have read the Contributing Guide.
• I have ensured that I am targeting the develop branch.
• I have updated the documentation accordingly.
• I have updated the tests accordingly.
• I have added an entry in the CHANGELOG.

[rasa]

@ScoopInstaller/maintainers : Should we instead create a "nirsoft2" bucket to allow users to "upgrade" to the new bucket when they're ready?

[rashil2000]

@ScoopInstaller/maintainers : Should we instead create a "nirsoft2" bucket to allow users to "upgrade" to the new bucket when they're ready?

I don't think that should be necessary.

However, I would like to stress again on the fact that we need more bucket maintainers, since more and more buckets are getting moved into the ScoopInstaller org. Should we make a community call for Nirsoft bucket, preferably before this PR is actually merged?