DXCDT-520: Use a custom client with retries for auth0 api client config

[sergiught]

🔧 Changes

go-auth0@v1 introduced a new way of expressing retry logic when instantiating the management client. This change is a deviation from v0 which implemented unlimited retries by default. Even with three retries, users are experiencing issues #273 (comment) due to the requests running in parallel and multiple failing at the same time, quickly hitting the 3 retry count.

In this PR we skip using the retry logic from the Go SDK and introduce a custom client that will:

• Retry an unlimited amount of times when hitting a rate limit error, after waiting the amount of time specified in the X-RateLimit-Reset header.
• Retry up to 3 times transient errors with exponential backoff and jitter.
• Retry up to 3 times on 500s with exponential backoff and jitter.

📚 References

🔬 Testing

• E2E tests passing against this branch: https://github.com/auth0/terraform-provider-auth0/actions/runs/5974520479/job/16210039505
• Ran manual tests with parallelism 23 and 23 managed resources, no issues.

📝 Checklist

• All new/changed/fixed functionality is covered by tests (or N/A)
• I have added documentation for all new/changed functionality (or N/A)

[codecov-commenter]

Codecov Report

Merging #788 (724f4e2) into patch/fix-cert-in-test (c0c49ef) will increase coverage by 0.02%.
The diff coverage is 95.23%.

Additional details and impacted files

@@                    Coverage Diff                     @@
##           patch/fix-cert-in-test     #788      +/-   ##
==========================================================
+ Coverage                   90.41%   90.43%   +0.02%     
==========================================================
  Files                          99       99              
  Lines                       13122    13184      +62     
==========================================================
+ Hits                        11864    11923      +59     
- Misses                        891      893       +2     
- Partials                      367      368       +1     

Files Changed	Coverage Δ
internal/config/config.go	97.50% <95.23%> (-2.50%)	⬇️

[sergiught]

This happened in here: https://github.com/auth0/terraform-provider-auth0/actions/runs/5974520479/job/16208826703#step:4:302.

[willvedd]

Great 👍