Make more parts of the migration deterministic

[turbolent]

Work towards onflow/cadence#3366

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 83.33333% with 10 lines in your changes are missing coverage. Please review.

Project coverage is 55.83%. Comparing base (e68a199) to head (932b678).

Files	Patch %	Lines
cmd/util/ledger/util/registers/registers.go	0.00%	6 Missing ⚠️
...til/ledger/migrations/fix_broken_data_migration.go	66.66%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #5979   +/-   ##
=======================================
  Coverage   55.82%   55.83%           
=======================================
  Files        1129     1129           
  Lines       89214    89260   +46     
=======================================
+ Hits        49806    49840   +34     
- Misses      34654    34660    +6     
- Partials     4754     4760    +6     

Flag	Coverage Δ
unittests	55.83% <83.33%> (+<0.01%)	⬆️

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