Revert "feat: Update SECURE_ANALYZER_PREFIX in all Sec Section templates"

What does this MR do and why?

Reverts !79063 (merged) due to an incident declaration where images are not properly being located.

See incident gitlab-com/gl-infra/production#6313 (closed).

Root cause is likely related to projects which override rules per job. Since the previous MR relies on dynamic setting of rules:variables these variables are not being set and the correct registry location is not being fetched. Since we cannot expect rules to not be overridden we must revert the MR and explore a different approach.

Screenshots or screen recordings

ERROR: Job failed: failed to pull image "registry.gitlab.com/security-products/gemnasium:2" with specified policies [always]: Error response from daemon: pull access denied for registry.gitlab.com/security-products/gemnasium, repository does not exist or may require 'docker login': denied: requested access to the resource is denied (manager.go:203:0s)

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