FIX: Remove HEAD -> GET request swap workaround

[vcastane]

Description

Remove a workaround replacing HEAD requests with GET requests for async requests. This workaround is no longer needed after the underlying bug was fixed in https://github.com/aio-libs/aiohttp/pull/5012

Issues Resolved

Partially resolves https://github.com/opensearch-project/opensearch-py/issues/698 The rest of the issue is user (my) error.

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 72.16%. Comparing base (bd91530) to head (9560795). Report is 52 commits behind head on main.

Files	Patch %	Lines
opensearchpy/_async/http_aiohttp.py	50.00%	1 Missing :warning:
opensearchpy/connection/http_async.py	50.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #699 +/- ## ========================================== + Coverage 72.14% 72.16% +0.01% ========================================== Files 89 89 Lines 7945 7943 -2 ========================================== Hits 5732 5732 + Misses 2213 2211 -2 ```

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[dblock]

Is there a way to write a test for this, too? Something that fails without this change?

[saimedhi]

Do we need to lock aiohttp >= a certain version as part of the PR?

• Bug resolved in aiohttp version 3.7.0.
• opensearch-py compatibility: aiohttp>=3,<4.
• I suggest instead of locking aiohttp to >=3.7.0,<4, we should check the aiohttp version and conditionally remove the workaround for aiohttp >=3.7.0.
• Detailed code review required to identify necessary code changes.

[saimedhi]

• I suggest instead of locking aiohttp to >=3.7.0,<4, we should check the aiohttp version and conditionally remove the workaround for aiohttp >=3.7.0.

Disregard the previous comment. To resolve this issue #715 , we're planning to lock aiohttp to >=3.9.2,<4. Thus, simply removing the workaround should suffice."

[saimedhi]

Hello @vcastane ,

Could you please take a look at finishing this PR when you have a moment? If you need any help, let us know.

Thanks a lot!

[dblock]

Finished this in https://github.com/opensearch-project/opensearch-py/pull/794.