[runtime] Update tos sdk version to 2.8.0

[brosoul]

Pull Request Description

Update tos sdk version to 2.8.0.
The download speed by the TOS SDK(2.8.0) can be almost as fast as the CLI tool.

Related Issues

Resolves: #[Insert issue number(s)]

Important: Before submitting, please complete the description above and review the checklist below.

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