workflow: don't exit on Linux runners; set SHOULD_CONTINUE env var instead - #3

Bugbot Analysis Progress (38s elapsed)

✅ Gathered PR context (2s)
✅ Analyzed code changes (1s)
✅ Completed bug detection — 0 potential bugs found (35s)
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✅ Posted analysis results — 0 bugs reported (0s)
✅ Analysis completed successfully (0s)

Final Result: Bugbot completed review - no issues found! ✅

Request ID: serverGenReqId_0c4f21a0-682f-4a45-b76a-3db8b2277275