Allow unsafe legacy tx when tracing txs before v6.3.0

[codchen]

Describe your changes and provide context

We will disallow unsafe tx starting v6.3.0, but unsafe txs that were sent before v6.3.0 should still be traceable

Testing performed to validate your change

tested on rpc node

[github-actions]

The latest Buf updates on your PR. Results from workflow Buf / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Jan 16, 2026, 1:48 AM

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 43.32%. Comparing base (1952adf) to head (8e136a1).
⚠️ Report is 1 commits behind head on tony/v6.3.

Files with missing lines	Patch %	Lines
x/evm/ante/preprocess.go	0.00%	0 Missing and 1 partial ⚠️

❌ Your patch status has failed because the patch coverage (0.00%) is below the target coverage (70.00%). You can increase the patch coverage or adjust the target coverage.
❌ Your project status has failed because the head coverage (38.19%) is below the target coverage (40.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@              Coverage Diff              @@
##           tony/v6.3    #2704      +/-   ##
=============================================
- Coverage      43.32%   43.32%   -0.01%     
=============================================
  Files           1866     1866              
  Lines         155279   155279              
=============================================
- Hits           67274    67272       -2     
+ Misses         82001    82000       -1     
- Partials        6004     6007       +3     

Flag	Coverage Δ
sei-chain	42.46% <0.00%> (-0.01%)	⬇️
sei-cosmos	37.95% <ø> (-0.01%)	⬇️
sei-db	44.92% <ø> (ø)
sei-ibc-go	55.96% <ø> (ø)
sei-tendermint	47.54% <ø> (+<0.01%)	⬆️
sei-wasmd	41.56% <ø> (ø)
sei-wasmvm	39.88% <ø> (ø)

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

Files with missing lines	Coverage Δ
x/evm/ante/preprocess.go	77.50% <0.00%> (ø)

... and 11 files with indirect coverage changes

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[masih]

Beyond a scope of this PR and a prexisting pattern: I have raised this issue in previous reviews: if we ever hit double digits major/minor strings.Compare will become incorrect since it sorts lexicographically.