Remove official docker images & move testing images to test folder

[aphralG]

Proposed changes

Removed official docker images from scripts folder
Moved test images from scripts folder to test folder
Removed official docker image make targets

Should be merged after #827

Checklist

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• I have read the CONTRIBUTING document
• I have run make install-tools and have attached any dependency changes to this pull request
• If applicable, I have added tests that prove my fix is effective or that my feature works
• If applicable, I have checked that any relevant tests pass after adding my changes
• If applicable, I have updated any relevant documentation (README.md)
• If applicable, I have tested my cross-platform changes on Ubuntu 22, Redhat 8, SUSE 15 and FreeBSD 13

[github-actions]

✅ All required contributors have signed the F5 CLA for this PR. Thank you!
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[aphralG]

I have hereby read the F5 CLA and agree to its terms

[oliveromahony]

@nginx-seanmoloney do we need a release note for this?