bump milvus to 2.4.8

[yellow-shine]

What this PR does / why we need it:

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [ ] Chart Version bumped
• [ ] Variables are documented in the README.md
• [ ] Title of the PR starts with chart name (e.g. [mychartname])
• [ ] PR only contains changes for one chart

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: LoveEachDay, yellow-shine

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/zilliztech/milvus-helm/blob/master/OWNERS)~~ [LoveEachDay,yellow-shine] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment