Backport disable v1 package metadata sync

What does this MR do and why?

This MR disables package_metadata synchronization v1 (feature flag package_metadata_synchronization) since it is superseded by v2 version_format (feature flag compressed_package_metadata_synchronization).

This changes was initially planned to be released in 16.3 with this MR !129405 (merged) but it did not make the cut off.

This change needs to be backported because Backport Enable sync with package metadata db b... (!131070 - merged) (enables package_metadata synchronization for all package registry types) has been backported to 16.3.3. Instances that have the v1 feature flag enabled will get the redundant data leading to excessive resource use: !131070 (comment 1569622123)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch.
• The MR that fixed the bug on the default branch has been deployed to GitLab.com (not applicable for documentation or spec changes).
• This MR has a severity label assigned (if applicable).
• This MR has been approved by a maintainer (only one approval is required).
• Ensure the e2e:package-and-test-ee job has either succeeded or been approved by a Software Engineer in Test.

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