fix: close the compressed readers after processing metadata

[kruskall]

From the documentation:

It is the caller's responsibility to call Close on the ReadCloser when done.

Should only affect compressed requests.

[ghost]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2022-08-04T04:36:53.803+0000

• Duration: 8 min 36 sec

Test stats 🧪

Test	Results
Failed	0
Passed	98
Skipped	32
Total	130

🤖 GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)