CI flake: unity-testsuite

[clockwork-labs-bot]

Detected by CI Gremlin after a failed GitHub Actions attempt succeeded on rerun.

Tests:

• unity-testsuite

Error:
[Licensing::Client] Error: Code 20100 while processing request (status: serial is not assigned to you, please contact the owner of the organization.)
[Licensing::Module] License activation has failed. Aborting.

Failed job runs:

• https://github.com/clockworklabs/SpacetimeDB/actions/runs/34479795279/job/102915397174 (unity-testsuite, attempt 2 -> 3)

Timeout detection:

• none

Context:

• none

[clockwork-labs-bot]

Diagnosis for the exact linked job/attempt: run 34479795279, job 102915397174, unity-testsuite, attempt 2.

GitHub's job API reports the linked job as run_attempt: 2, matching the ticket's failed attempt 2 -> 3 rerun. This was public CI for bot/revert-skip-unity-5909 (CI - Re-enable unity jobs), head SHA 05dc26656db5b6258f7d3e9bcfbd2bb74ba844ae, on runner ghr-github-self-hosted-ubuntu-14900k-01-spacetimedb-14-07ec9daa.

The setup path completed before the failure: bindings generation, dirty-check, local C# package build, Unity meta check, and the test-runner setup all reached Unity license activation. game-ci/unity-test-runner@v4 then retried Unity professional serial activation four times. Each activation connected to Unity and updated the access token successfully, then failed with:

[Licensing::Client] Error: Code 20100 while processing request (status: serial is not assigned to you, please contact the owner of the organization.)

The exact-attempt root cause is Unity/GameCI license activation rejecting the configured serial as not assigned to the account, before Unity playmode tests ran. This is CI/licensing infrastructure, not a SpacetimeDB Unity test assertion.

Suggested title: CI flake: unity-testsuite Unity serial is not assigned to account

Duplicate search: I searched exact and broad public terms including serial is not assigned to you, Unity license activation, Unity entitlement license, Unity serial activation, Access token is unavailable, and the older Unity headless-license strings. I found related public Unity licensing flakes, including #5913/#5914 for serial maximum activations and #5581/#5838/#5874 for headless entitlement/license-not-active failures, but those are different Unity licensing failure modes.

Top duplicate candidate: no close duplicate found. Similar Unity licensing tickets exist, but none are close enough to mark this as a duplicate.