Publishing to RubyGems with MFA through automated workflows is not supported

[stefannibrasil]

A few months ago, we merged this workflow to publish faker releases to Ruby Gems automatically. However, Ruby Gems automatic releases does not support Multi-factor authentication (MFA) yet.

While Ruby Gems automatic releases with MFA is not supported, every time we make a release on faker, we get a failure notification for the publish workflow.

Since it's not supported and we don't want to keep carrying unused code, let's remove it for now. Once RubyGems adds this support, we can add it back.

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This issue is great for a beginner, so please choose another way to contribute to faker if you have already contributed to other open source projects.