feat: support SMI TrafficSplit v1alpha4

[addozhang]

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional with a list of types and scopes found here, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I've signed my commits with DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My builds are green. Try syncing with master if they are not.
• My organization is added to USERS.md.

As we know the SMI has bean archived, but some SMI implementations like FSM are still using SMI TrafficSplit v1alpha4. Before migrating to Gateway API, it still requires the progressive rollout provided by Argo Rollout.

[codecov]

Codecov Report

Attention: Patch coverage is 96.22642% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 78.26%. Comparing base (8405f2e) to head (2543f25).
Report is 102 commits behind head on master.

Files	Patch %	Lines
rollout/trafficrouting/smi/smi.go	96.22%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3587      +/-   ##
==========================================
- Coverage   81.83%   78.26%   -3.58%     
==========================================
  Files         135      158      +23     
  Lines       20688    18450    -2238     
==========================================
- Hits        16931    14440    -2491     
- Misses       2883     3102     +219     
- Partials      874      908      +34     

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[github-actions]

Go Published Test Results

2 165 tests   2 165 ✅  2m 54s ⏱️
  119 suites      0 💤
    1 files        0 ❌

Results for commit 2543f25.

♻️ This comment has been updated with latest results.

[sonarcloud]

Quality Gate failed

Failed conditions
43.0% Duplication on New Code (required ≤ 40%)

See analysis details on SonarCloud

[github-actions]

E2E Tests Published Test Results

  4 files    4 suites   3h 24m 50s ⏱️
110 tests  97 ✅  6 💤  7 ❌
456 runs  416 ✅ 24 💤 16 ❌

For more details on these failures, see this check.

Results for commit 2543f25.