chore(deps): update debian docker tag to v12.6 (#340)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| debian | final | minor | `12.5` -> `12.6` |

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dockerfiles/ee-apps/ats/Dockerfile

@@ -1,5 +1,5 @@
 # Ref: https://github.com/sqawasmi/trafficserver-docker/blob/master/Dockerfile
-FROM debian:12.5
+FROM debian:12.6
 
 LABEL org.opencontainers.image.authors "wuhui.zuo@pingcap.com"
 LABEL org.opencontainers.image.source = "https://github.com/PingCAP-QE/artifacts"