Patch `grape-entity` to prevent having NameError loop

What does this MR do?

RubyVM starts raising NameError errors in case of an error in our Grape::Entity instances because of a bug existing in the gem's upstream version.

This causes high CPU usage and puts us at the risk of having DoS. The VM would eventually raise a SystemStackError but this takes quite long because the repeating frames are huge.

In this MR, I propose monkey-patching the grape-entity gem until the upstream version gets fixed.

Related to #329436 (closed).

Does this MR meet the acceptance criteria?

Conformity

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• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

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Security

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• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team