Disable builtin ssl_session_cache

[sepich]

What this PR does / why we need it:

Fix for: #7080
From docs:

builtin
a cache built in OpenSSL; Use of the built-in cache can cause memory fragmentation.

using only shared cache without the built-in cache should be more efficient.

One could still set builtin if needed via ssl-session-cache-size

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

fixes #7080

How Has This Been Tested?

Tested via overriding whole nginx.tmpl

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added tests to cover my changes.
• All new and existing tests passed.

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[strongjz]

/ok-to-test

[strongjz]

/kind bug
/triage accepted

[rikatz]

woooaaa good catch @sepich

I will reserve some time later just to check some future impact, otherwise lgtm

[ElvinEfendi]

/lgtm

We have been running without builtin SSL caching for a long time already at my company. For some reason I had an impression that I upstream'd the change, but apparently I did not 😄

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ElvinEfendi, sepich

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[ElvinEfendi]

/hold

I meant to only lgtm, not approve. I'll let another maintainer to approve too before we merge this.

[rikatz]

/hold cancel
Well, I think we can merge this

@sepich thanks for sticking with us and finding a fix for this bug!

@strongjz is going to make a live release on Kubecon next week (kidding, we can work on this during the weekend!)

Remember to cherry-pick this to "legacy" branch as this gets merged so we can implement this bug fix on 0.X as well

[sepich]

Remember to cherry-pick this to "legacy" branch as this gets merged so we can implement this bug fix on 0.X as well

Sure, #7779