Update Docker CI tags to 20251206-185d63a (flashinfer-ai#2184)

This PR updates the Docker CI image tags to the latest version:
`20251206-185d63a`

Updated images:
- flashinfer/flashinfer-ci-cu126:20251206-185d63a
- flashinfer/flashinfer-ci-cu128:20251206-185d63a
- flashinfer/flashinfer-ci-cu129:20251206-185d63a
- flashinfer/flashinfer-ci-cu130:20251206-185d63a

Auto-generated by [release-ci-docker
workflow](https://github.com/flashinfer-ai/flashinfer/actions/runs/19993421764)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Chores**
* Updated CI build container images to latest versions for improved
build reliability and security.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Co-authored-by: yzh119 <11773619+yzh119@users.noreply.github.com>

Author: flashinfer-bot

ci/docker-tags.yml

@@ -1,4 +1,4 @@
-flashinfer/flashinfer-ci-cu126: 20251205-54c1678
-flashinfer/flashinfer-ci-cu128: 20251205-54c1678
-flashinfer/flashinfer-ci-cu129: 20251205-54c1678
-flashinfer/flashinfer-ci-cu130: 20251205-54c1678
+flashinfer/flashinfer-ci-cu126: 20251206-185d63a
+flashinfer/flashinfer-ci-cu128: 20251206-185d63a
+flashinfer/flashinfer-ci-cu129: 20251206-185d63a
+flashinfer/flashinfer-ci-cu130: 20251206-185d63a