Refactor sync fallback to apropriately validate and re-excute as necessary

[udpatil]

Describe your changes and provide context

This refactors the sync fallback such that it will re-execute (and revalidate validated to determine if they need execution) synchronously after exceeding maxIterations

Testing performed to validate your change

Unit test + need to perform loadtesting on main, some loadtesting performed one the seiv2 version

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 73.07692% with 7 lines in your changes are missing coverage. Please review.

Project coverage is 55.44%. Comparing base (df756ef) to head (f7f3843).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #461      +/-   ##
==========================================
- Coverage   55.46%   55.44%   -0.02%     
==========================================
  Files         629      629              
  Lines       53529    53541      +12     
==========================================
- Hits        29689    29688       -1     
- Misses      21729    21740      +11     
- Partials     2111     2113       +2     

Files	Coverage Δ
store/multiversion/store.go	90.96% <100.00%> (+0.06%)	⬆️
tasks/scheduler.go	89.97% <70.83%> (-3.44%)	⬇️