#12113 changed admission control to reject with 429 instead of 503.
failoverWriter only held back responses with status >= 500, so a 429
rejection reached the client and the chain never spilled to its next
target.
Hold 429 as well. An admission rejection is still flagged and spills
without tripping the target. Any other 429 is not retryable, so it is
released to the client unchanged.
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: Claude:claude-opus-5-5 [Claude Code]
Ettore Di Giacinto
d8571a8ee9