[Build] Increase sleep time in InteropTests to attempt to reduce CI failures

[daverayment]

Summary of the Pull Request

Increase sleep duration while waiting for IPC setup in the interop unit test.

A number of PRs have had failures recently even though they do not touch interop, likely due to this sleep being too short. An existing comment points to the addition of the delay being because of this, and resource-constrained build agents/environments could need a longer duration.

PR Checklist

• Closes: #xxx

• Communication: I've discussed this with core contributors already. If the work hasn't been agreed, this work might be rejected
• Tests: Added/updated and all pass
• Localization: All end-user-facing strings can be localized
• Dev docs: Added/updated
• New binaries: Added on the required places
  • JSON for signing for new binaries
  • WXS for installer for new binaries and localization folder
  • YML for CI pipeline for new test projects
  • YML for signed pipeline
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

See comments on #47211 and #48106.

Validation Steps Performed

N/A

[crutkas]

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