[Testing] Add regression tests for network data race fixes

[janezpodhostnik]

Adds deterministic regression coverage for the network-layer race fixes from #8633. Each new test was verified to fail (assertion failure or -race report) with the corresponding fix reverted, and to pass with it.

Changes

• network/slashing: first tests for the package. Verify the violations consumer does not mutate the caller's Violation and that one violation can be reported concurrently through all entry points.
• RPC inspector: verify async inspection does not mutate the inspected RPC (the publish message list stays byte-for-byte in place), since libp2p pubsub keeps using the RPC concurrently.
• ALSP SpamRecordCache: same-record concurrent Get/AdjustWithInit test. The existing concurrency tests only exercised disjoint records and did not catch the race. Also verifies the returned penalty is the one produced by the caller's own adjustment.
• AppSpecificScoreCache: same-peer concurrent update/read test, for the same reason.
• Scoring registry: unit test for the silence-period state machine, including the new "registry not started yet" branch (previously the zero start time spuriously ended the silence period before startup).

Related: #8633

---

^{Need help on this PR? Tag @codesmith-bot with what you need. Autofix is disabled.}

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: e9f3a04c-0260-4cf8-a1c2-15b7388283ae

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}