chore(deps): update golang version to 1.21

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
go (source)	golang	minor	1.20 -> 1.21
golang	stage	minor	1.20.6-bookworm -> 1.21.3-bookworm
golang	final	minor	1.20.6-bookworm -> 1.21.3-bookworm

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Release Notes

golang/go (go)

### [`v1.21.3`](https://togithub.com/golang/go/compare/go1.21.2...go1.21.3) ### [`v1.21.2`](https://togithub.com/golang/go/compare/go1.21.1...go1.21.2) ### [`v1.21.1`](https://togithub.com/golang/go/compare/go1.21.0...go1.21.1) ### [`v1.21.0`](https://togithub.com/golang/go/compare/go1.20.8...go1.21.0) ### [`v1.20.10`](https://togithub.com/golang/go/compare/go1.20.9...go1.20.10) ### [`v1.20.9`](https://togithub.com/golang/go/compare/go1.20.8...go1.20.9) ### [`v1.20.8`](https://togithub.com/golang/go/compare/go1.20.7...go1.20.8) ### [`v1.20.7`](https://togithub.com/golang/go/compare/go1.20.6...go1.20.7) ### [`v1.20.6`](https://togithub.com/golang/go/compare/go1.20.5...go1.20.6) ### [`v1.20.5`](https://togithub.com/golang/go/compare/go1.20.4...go1.20.5) ### [`v1.20.4`](https://togithub.com/golang/go/compare/go1.20.3...go1.20.4) ### [`v1.20.3`](https://togithub.com/golang/go/compare/go1.20.2...go1.20.3) ### [`v1.20.2`](https://togithub.com/golang/go/compare/go1.20.1...go1.20.2) ### [`v1.20.1`](https://togithub.com/golang/go/compare/go1.20...go1.20.1)

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