Update module github.com/urfave/cli/v2 to v2.4.8

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
github.com/urfave/cli/v2	require	patch	v2.4.7 -> v2.4.8

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Release Notes

urfave/cli

### [`v2.4.8`](https://togithub.com/urfave/cli/releases/v2.4.8) [Compare Source](https://togithub.com/urfave/cli/compare/v2.4.7...v2.4.8) #### What's Changed - Allow -ve values for int, float & duration by [@​dearchap](https://togithub.com/dearchap) in [https://github.com/urfave/cli/pull/1262](https://togithub.com/urfave/cli/pull/1262) **Full Changelog**: https://github.com/urfave/cli/compare/v2.4.7...v2.4.8

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