downstream opm server change to use pre-existent cache

Jira Description

As an OPM maintainer, I want to downstream the PR for (OCP 4.12 ) and backport it to OCP 4.11 so that IIB will NOT be impacted by the changes when it upgrades the OPM version to use the next/future opm upstream release (v1.25.0).

Summary / Background

IIB(the downstream service that manages the indexes) uses the upstream version and if they bump the OPM version to the next/future (v1.25.0) release with this change before having the downstream images updated then: the process to manage the indexes downstream will face issues and it will impact the distributions. 

Acceptance Criteria

• The changes in the PR are available for the releases which uses FBC -> OCP 4.11, 4.12

Definition of Ready

• PRs merged into downstream OCP repos branches 4.11/4.12

Definition of Done

• We checked that the downstream images are with the changes applied (i.e.: we can try to verify in the same way that we checked if the changes were in the downstream for the fix OLM-2639 )