fix: return error when --format and --pretty are both used

[wangxiaoxuan273]

What this PR does / why we need it:
return error when --format and --pretty are both used for oras manifest fetch. Need to rebase after #1354 is merged.

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 #1356

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]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.71%. Comparing base (23e243b) to head (03b3c9d).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1359   +/-   ##
=======================================
  Coverage   84.70%   84.71%           
=======================================
  Files         104      104           
  Lines        3687     3689    +2     
=======================================
+ Hits         3123     3125    +2     
  Misses        336      336           
  Partials      228      228           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[qweeah]

LGTM