Allow multiple getPayload calls for a delivered payload

[avalonche]

📝 Summary

Allow multiple get payload calls if the block hashes match for the slot.

⛱ Motivation and Context

Supporting #397 to allow repeated getPayload requests for an already delivered payload. Improves redundancy for get payload requests

📚 References

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✅ I have run these commands

• make lint
• make test-race
• go mod tidy
• I have seen and agree to CONTRIBUTING.md

[codecov-commenter]

Codecov Report

Merging #400 (a4795d0) into main (42dfeca) will increase coverage by 0.14%.
The diff coverage is 53.57%.

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@@            Coverage Diff             @@
##             main     #400      +/-   ##
==========================================
+ Coverage   22.47%   22.62%   +0.14%     
==========================================
  Files          21       21              
  Lines        4111     4128      +17     
==========================================
+ Hits          924      934      +10     
- Misses       3060     3066       +6     
- Partials      127      128       +1     

Flag	Coverage Δ
unittests	22.62% <53.57%> (+0.14%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
services/api/service.go	22.55% <0.00%> (-0.07%)	⬇️
datastore/redis.go	66.01% <83.33%> (+0.41%)	⬆️

[michaelneuder]

LGTM! nice fix