Add a 60-second leeway to the JWT validation logic

[liudonggalaxy]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Other, please describe:

When an identity provider (IDP) is implemented using the Authlib library, a machine client connecting to the IDP via the client credentials flow—using the client secret JWT or other JWT-based methods—may occasionally encounter an Invalid client error. This issue arises because the local time on the client's machine can sometimes be one or two seconds ahead of the IDP's time. As a result, the iat claim in the client-signed JWT appears to be in the future, causing the IDP to reject it. To resolve this, a 60-second leeway can be added to the JWT validation logic.

Does this PR introduce a breaking change? (check one)

• Yes
• No

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