Updating Gemfile.lock for security alerts

[jwillenbring]

I regenerated Gemfile.lock to address recent dependabot alerts:

https://github.com/trilinos/trilinos.github.io/security/dependabot/28

https://github.com/trilinos/trilinos.github.io/security/dependabot/27

I am quite frankly not an expert in Gemfiles, but this approach was successful for both

Mantevo https://mantevo.github.io/

and

Tramonto https://tramonto.github.io/

Here is the PR for Tramonto: https://github.com/Tramonto/tramonto.github.io/pull/9