ci(lint): bound the advisory public-surface step so it can't time out the blocking footguns job (#106103)

The 'Public-surface diff vs base (advisory)' step already carries
continue-on-error: true, so its own failure never fails the Windows-footguns
job. But continue-on-error does not shield the job-level timeout-minutes: 5:
when the deepen/fetch loop runs long (a distant or missing merge-base), the
step eats the whole job budget and the job is cancelled at ~5m even though the
blocking footgun/compat checks passed and the public-surface check is advisory.

Give the advisory step its own timeout-minutes: 2. A step overrun is then
killed and, via continue-on-error, kept off the job outcome the same way a
step failure already is, so the blocking job can finish under its budget.
Fixes #106103.

.github/workflows/lint.yml

@@ -193,6 +193,11 @@ jobs:
       - name: Public-surface diff vs base (advisory)
         if: github.event_name == 'pull_request'
         continue-on-error: true
+        # Bound the advisory step so a long deepen/fetch (e.g. a distant or missing
+        # merge-base) can't consume the blocking job's 5-minute budget and cancel it.
+        # continue-on-error already keeps a step *failure* off the job; a step-level
+        # timeout keeps a step *overrun* off the job-level timeout the same way.
+        timeout-minutes: 2
         run: |
           git fetch --no-tags --deepen=200 origin "${{ github.base_ref }}" HEAD
           for i in 1 2 3; do