Use dependency proxy for base images

What does this MR do?

Use dependency proxy for fetching images from Docker Hub.

This is relying on !51927 (merged)

Please consider the effect of the changes in this Merge Request on the following:

• Effects on different pipeline types
  • This applies to the job directly, which is unrelated to rules.
• Effects on non-canonical projects (gitlab-foss, security, etc)
  • All projects under gitlab-org should be the same.
• Effects on pipeline performance
  • Oddly, I often see 3s from Docker Hub and 4s from Dependency Proxy, which seems to imply that Dependency Proxy might be slower. But the precision is not enough and it's difficult to say the actual difference from knowing only this number.
  • 4s for pulling from Dependency Proxy: https://gitlab.com/gitlab-org/gitlab/-/jobs/1004516455
  • 3s for pulling from Docker Hub: https://gitlab.com/godfat/gitlab/-/jobs/1005210620
• Effects on fork pipelines
  • Fall back to Docker Hub: !52705 (merged)

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #296619 (closed)