fix(sarif): guard optional chain in baseline.test.ts for Biome 2.5.3

[theagenticguy]

What

Add the optional-chaining operator (?.) to two spots in packages/sarif/src/baseline.test.ts where an optional chain was followed by a non-optional member access on the next line:

const state = (tagged.runs[0]?.results?.[0] as unknown as { baselineState?: string })
  ?.baselineState;  // was: .baselineState

Why

Biome 2.5.3 tightened lint/correctness/noUnsafeOptionalChaining. The pre-existing code on main (lines 135 and 174) short-circuits tagged.runs[0]?.results?.[0] to undefined, then reads .baselineState on it — which would throw TypeError at runtime. Biome now flags this as an error.

Verified locally against @biomejs/biome@2.5.3: the unfixed file emits 2 noUnsafeOptionalChaining errors; the fixed file passes clean.

Impact

• Fixes a real latent bug on main independent of any dep bump.
• Unblocks the Biome 2.5.2 → 2.5.3 bump in the typescript-tooling group (build(deps-dev): bump the typescript-tooling group with 2 updates #287), whose lint + self-scan jobs fail on exactly this code.
• Behavior unchanged on the passing path (value present); if the chain were ever undefined, the assertion now fails on value mismatch instead of a raw TypeError.

🤖 Opened by Bonk nightly maintenance.