fix: resolve duplicated debug log for oras cp

[qweeah]

What this PR does / why we need it:
This PR fixes a bug that causes duplicated numbering for debug logs

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #1096

Please check the following list:

• Does the affected code have corresponding tests, e.g. unit test, E2E test?
• Does this change require a documentation update?
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have an appropriate license header?

[codecov-commenter]

Codecov Report

Merging #1139 (9ab60bb) into main (f1ef429) will decrease coverage by 0.06%.
The diff coverage is 100.00%.

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@@            Coverage Diff             @@
##             main    #1139      +/-   ##
==========================================
- Coverage   80.79%   80.73%   -0.06%     
==========================================
  Files          64       64              
  Lines        3374     3374              
==========================================
- Hits         2726     2724       -2     
- Misses        447      449       +2     
  Partials      201      201              

Files	Coverage Δ
internal/trace/transport.go	82.35% <100.00%> (ø)

... and 1 file with indirect coverage changes

[shizhMSFT]

LGTM