Deprecate Generators with External Calls

[stefannibrasil]

[this issue will be assigned to participants of the RubyConf2023 Hack Day]

Some generators pull data from external services. We would like to move away from depending on external services.

As part of this task:

• list out any generators that make external calls
• add a deprecation message to these generators

Here's an example of how to deprecate a generator:

• https://github.com/faker-ruby/faker/pull/2733

[vveleva]

Currently working on this one!

[raysapida]

I saw two other generators, Placeholdit and Avatar, that used URLs but it doesn't look like they were calling the service

[stefannibrasil]

Thank you @raysapida for working on this! Now we know for sure we are not relying on any external services.