fix(tts): don't mark FallbackAdapter primary unavailable on abort-before-first-audio#1290

mrniket wants to merge 2 commits intolivekit:mainlivekit/agents-js:mainfrom

lottiehq-oss:fix/tts-fallback-abort-no-mark-unavailablelottiehq-oss/agents-js:fix/tts-fallback-abort-no-mark-unavailableCopy head branch name to clipboard