fix: HierarchyPager used instead of FlatPager to adhere bulk insert failure on using Azure buckets

[gifi-siby]

Related task: #39135

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: gifi-siby
To complete the pull request process, please assign jiaoew1991 after the PR has been reviewed.
You can assign the PR to them by writing /assign @jiaoew1991 in a comment when ready.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• internal/storage/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[mergify]

@gifi-siby Thanks for your contribution. Please submit with DCO, see the contributing guide https://github.com/milvus-io/milvus/blob/master/CONTRIBUTING.md#developer-certificate-of-origin-dco.

[mergify]

@gifi-siby

Invalid PR Title Format Detected

Your PR submission does not adhere to our required standards. To ensure clarity and consistency, please meet the following criteria:

1. Title Format: The PR title must begin with one of these prefixes:

• feat: for introducing a new feature.
• fix: for bug fixes.
• enhance: for improvements to existing functionality.
• test: for add tests to existing functionality.
• doc: for modifying documentation.
• auto: for the pull request from bot.

2. Description Requirement: The PR must include a non-empty description, detailing the changes and their impact.

Required Title Structure:

[Type]: [Description of the PR]

Where Type is one of feat, fix, enhance, test or doc.

Example:

enhance: improve search performance significantly 

Please review and update your PR to comply with these guidelines.

[mergify]

@gifi-siby E2e jenkins job failed, comment /run-cpu-e2e can trigger the job again.

[mergify]

@gifi-siby go-sdk check failed, comment rerun go-sdk can trigger the job again.

[mergify]

@gifi-siby cpp-unit-test check failed, comment rerun cpp-unit-test can trigger the job again.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 69.64%. Comparing base (4355b48) to head (9685b6c).
Report is 4 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #39149   +/-   ##
=======================================
  Coverage   69.64%   69.64%           
=======================================
  Files         296      296           
  Lines       26633    26633           
=======================================
  Hits        18548    18548           
  Misses       8085     8085           

Components	Coverage Δ
Client	∅ <ø> (∅)
Core	69.64% <ø> (ø)
Go	∅ <ø> (∅)

[mergify]

@gifi-siby go-sdk check failed, comment rerun go-sdk can trigger the job again.

[mergify]

@gifi-siby E2e jenkins job failed, comment /run-cpu-e2e can trigger the job again.

[gifi-siby]

/run-cpu-e2e

[gifi-siby]

rerun go-sdk

[mergify]

@gifi-siby E2e jenkins job failed, comment /run-cpu-e2e can trigger the job again.