CI flake: Lints

[clockwork-labs-bot]

Detected by CI Gremlin after a failed merge-queue run succeeded in a later merge-queue run without a new PR head commit.

Tests:

• Lints

Error:
error: explicit call to .into_iter() in function argument accepting IntoIterator
--> crates/schema/src/def/validate/v10.rs:412:31

Failed job runs:

• https://github.com/clockworklabs/SpacetimeDB/actions/runs/36054918470/job/107824022105 (Lints, attempt merge queue run 36054918470 -> merge queue run 36070769099)

Timeout detection:

• none

Context:

• Merge queue PR: Bump rust toolchain to 1.96.1 #5924
• PR head SHA: e8254f2
• Later successful run: https://github.com/clockworklabs/SpacetimeDB/actions/runs/36070769099

[clockwork-labs-bot]

Exact-attempt diagnosis for https://github.com/clockworklabs/SpacetimeDB/actions/runs/36054918470/job/107824022105:

• Run/job/attempt: CI run 36054918470, job 107824022105, attempt 1, Lints, merge-group head fc6a16bb661ba80511ec6211b7530eafcf304627 for PR Bump rust toolchain to 1.96.1 #5924.
• The failing step was Run ci lint, specifically cargo ci lint -> cargo clippy --timings --all --tests --benches -- -D warnings.
• Setup, checkout, Rust, Node, and pnpm setup all succeeded. The job failed when Clippy denied clippy::useless_conversion at crates/schema/src/def/validate/v10.rs:412: errors.extend(e.into_iter());. Clippy noted that extend already accepts IntoIterator and suggested removing .into_iter().
• Root cause for this exact job is a lint failure in the synthetic merge-queue tree, not a test failure, timeout, or runner/setup failure. The later successful merge-queue run used a different merge-group head SHA (930bedeb79dbfddfdac226d02af85971de568f12), so this looks like transient merge-queue/lint churn rather than a recurring runtime flake.

Suggested title: CI flake: Lints: clippy::useless_conversion in validate/v10.rs

Duplicate search:

• Searched public Test Flakes tickets and broader public/org issues for the exact error text, clippy useless_conversion, cargo ci lint / cargo clippy, Lints clippy, and crates/schema/src/def/validate/v10.rs.
• No close public duplicate found.

Top duplicate candidate: none. No duplicate closure applied.