[release/9.0] Caching SERedis critical bugfix; defer HC metadata detection because of DI cycle

[github-actions]

Backport of #60915 to release/9.0

/cc @mgravell

Caching SERedis critical bugfix; defer HC metadata detection because of DI cycle

Fix DI loop in metadata discovery - interaction between two components

Description

Unfortunately because the two components are in different repos, a fake was used to "prove" the setup here; this fake did not fully reproduce the DI demands, hance a cyclic interaction was not discovered. The test has been updated to reflect the real DI setup, and the code reworked.

Fixes #60894

Customer Impact

Attempts to use AddHybridCache() and AddStackExchangeRedis() together can cause DI to loop infinitely or until stack-overflow.

Regression?

• Yes - from 9.0.2
• No

Risk

• High
• Medium
• Low

Change is simple DI restructure only; no complex logic post construction, which is validated in tests.

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A

---

When servicing release/2.1

• Make necessary changes in eng/PatchConfig.props

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