deps: update dependency go to v1.26.3 (#1402)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [go](https://redirect.github.com/golang/go) | | patch | `1.26.2` →
`1.26.3` |
| [go](https://go.dev/)
([source](https://redirect.github.com/golang/go)) | toolchain | patch |
`1.26.2` → `1.26.3` |

---

### Release Notes

<details>
<summary>golang/go (go)</summary>

###
[`v1.26.3`](https://redirect.github.com/golang/go/compare/go1.26.2...go1.26.3)

[Compare
Source](https://redirect.github.com/golang/go/compare/go1.26.2...go1.26.3)

</details>

---

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go.mod

@@ -2,7 +2,7 @@ module github.com/hetznercloud/cli
 
 go 1.25.0
 
-toolchain go1.26.2
+toolchain go1.26.3
 
 require (
 	github.com/BurntSushi/toml v1.6.0

mise.toml

@@ -1,5 +1,5 @@
 [tools]
-go = "1.26.2"
+go = "1.26.3"
 "go:go.uber.org/mock/mockgen" = "v0.6.0"
 "github:golangci/golangci-lint" = "2.12.2"
 "github:goreleaser/goreleaser" = "v2.15.4"