[willing to PR] optimzation of eagle2

[jjjjohnson]

Checklist

• 1. I have searched related issues but cannot get the expected help.
• 2. The bug has not been fixed in the latest version.
• 3. Please note that if the bug-related issue you submitted lacks corresponding environment info and a minimal reproducible demo, it will be challenging for us to reproduce and resolve the issue, reducing the likelihood of receiving feedback.
• 4. If the issue you raised is not a bug but a question, please raise a discussion at https://github.com/sgl-project/sglang/discussions/new/choose Otherwise, it will be closed.
• 5. Please use English, otherwise it will be closed.

Describe the bug

The current target model verify implementmation has not check the EOS token, leading to looong output in some cases.

Reproduction

eagle2

Environment

main

[merrymercy]

@jjjjohnson please send the PR!

[jjjjohnson]

@merrymercy #2723