[SDTEST-437] Auto test retries for minitest

[anmarchenko]

What does this PR do?
Adds auto test retries support for minitest

How to test the change?
Feature is covered by unit tests in minitest/instrumentation_spec.rb

Tested using Sidekiq in this commit: anmarchenko/sidekiq@020ca88

Local test run ends successfully:

New flaky test is detected by Datadog:

Correct test runs are traced:

Retries can be filtered using test.is_retry tag:

Test session is reported as passed:

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 98.70130% with 2 lines in your changes missing coverage. Please review.

Project coverage is 98.88%. Comparing base (b891aaf) to head (067c735).

Files	Patch %	Lines
...atadog/ci/contrib/minitest/instrumentation_spec.rb	97.97%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #214      +/-   ##
==========================================
- Coverage   98.89%   98.88%   -0.01%     
==========================================
  Files         261      261              
  Lines       12096    12243     +147     
  Branches      544      552       +8     
==========================================
+ Hits        11962    12107     +145     
- Misses        134      136       +2     

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[datadog-staging-us1-crawler-test]

🔵 Code Quality Violation

Do not use class variables (...read more)

The rule "Avoid class variables" refers to the practice of refraining from using class variables (variables starting with '@@') in Ruby. Class variables are shared between a class and all of its descendants, which can lead to unexpected behavior and bugs that are difficult to trace. This is because if a class variable is changed in a subclass, that change will also affect the superclass and all other subclasses.

This rule is crucial for maintaining clean, predictable, and easy-to-debug code. It also helps to prevent unintentional side effects that can occur when class variables are manipulated in different parts of a program.

To adhere to this rule, consider using class instance variables or constants instead. Class instance variables belong solely to the class they are defined in, and their value does not get shared with subclasses. Constants, on the other hand, are a good option when the value is not meant to change. For example, in the given non-compliant code, the class variable @@class_var could be replaced with a class instance variable @class_var or a constant CLASS_VAR, depending on the intended use.

    

[datadog-datadog-staging-us1-all]

🔵 Code Quality Violation

Do not use class variables (...read more)

The rule "Avoid class variables" refers to the practice of refraining from using class variables (variables starting with '@@') in Ruby. Class variables are shared between a class and all of its descendants, which can lead to unexpected behavior and bugs that are difficult to trace. This is because if a class variable is changed in a subclass, that change will also affect the superclass and all other subclasses.

This rule is crucial for maintaining clean, predictable, and easy-to-debug code. It also helps to prevent unintentional side effects that can occur when class variables are manipulated in different parts of a program.

To adhere to this rule, consider using class instance variables or constants instead. Class instance variables belong solely to the class they are defined in, and their value does not get shared with subclasses. Constants, on the other hand, are a good option when the value is not meant to change. For example, in the given non-compliant code, the class variable @@class_var could be replaced with a class instance variable @class_var or a constant CLASS_VAR, depending on the intended use.