chore(deps): update korthout/backport-action action to v3

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
korthout/backport-action	action	major	v2 -> v3

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Release Notes

korthout/backport-action (korthout/backport-action)

### [`v3`](https://togithub.com/korthout/backport-action/compare/v2...v3) [Compare Source](https://togithub.com/korthout/backport-action/compare/v2...v3)

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