[fix](cloud) Batch flush packed file refs during rowset recycle

[wyxxxcat]

What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

Recycling rowsets that reference packed files previously updated packed-file metadata one rowset at a time. That produced repeated read-modify-write operations on the same packed-file record, increased contention, and delayed recycle-key cleanup until each individual update completed. This change aggregates packed-file references per file, flushes them in one pass, and only removes recycle metadata after the packed-file update succeeds.

Release note

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[hello-stephen]

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