Update Actions (major)

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v2 -> v3
actions/stale	action	major	v7 -> v8

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Release Notes

actions/checkout

### [`v3`](https://togithub.com/actions/checkout/blob/HEAD/CHANGELOG.md#v340) [Compare Source](https://togithub.com/actions/checkout/compare/v2...v3) - [Upgrade codeql actions to v2](https://togithub.com/actions/checkout/pull/1209) - [Upgrade dependencies](https://togithub.com/actions/checkout/pull/1210) - [Upgrade @​actions/io](https://togithub.com/actions/checkout/pull/1225)

actions/stale

### [`v8`](https://togithub.com/actions/stale/compare/v7...v8) [Compare Source](https://togithub.com/actions/stale/compare/v7...v8)

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