op-challenger: Support downloading prestates with a specific filename.

[ajsutton]

Description

Allows running the latest builds published from develop automatically.

[codecov]

Codecov Report

Attention: Patch coverage is 7.36842% with 88 lines in your changes missing coverage. Please review.

Project coverage is 42.60%. Comparing base (d39eb24) to head (38bd8c0).

Files with missing lines	Patch %	Lines
op-challenger/runner/prestates.go	0.00%	68 Missing ⚠️
op-challenger/runner/runner.go	0.00%	17 Missing ⚠️
op-challenger/runner/factory.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #14035      +/-   ##
===========================================
- Coverage    47.16%   42.60%   -4.56%     
===========================================
  Files          975      811     -164     
  Lines        81768    72507    -9261     
===========================================
- Hits         38562    30889    -7673     
+ Misses       40306    38899    -1407     
+ Partials      2900     2719     -181     

Flag	Coverage Δ
cannon-go-tests-32	?
cannon-go-tests-64	?
contracts-bedrock-tests	?

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

Files with missing lines	Coverage Δ
op-challenger/cmd/run_trace.go	40.00% <100.00%> (+4.28%)	⬆️
op-challenger/runner/factory.go	0.00% <0.00%> (ø)
op-challenger/runner/runner.go	0.00% <0.00%> (ø)
op-challenger/runner/prestates.go	0.00% <0.00%> (ø)

... and 173 files with indirect coverage changes