Go directive in go.mod is invalid

According to https://go.dev/issues/62278 a concrete go version has to include the
patch number or an additional toolchain directive. The project declares the version
as 1.22 which is invalid and will result in an error.

```
GOTOOLCHAIN="go1.21+auto" go1.22.4 mod tidy
go: downloading go1.22 (linux/amd64)
go: download go1.22 for linux/amd64: toolchain not available
```

We should change it to `go 1.22.0` as this is the first actual release of go 1.22. Another option is to specify a toolchain directive:

```
go 1.22
toolchain go1.22.0
```

Start with the go.mod file and inspect its current Go version directive. Change the project declaration to go 1.22.0, then run GOTOOLCHAIN="go1.21+auto" go1.22.4 mod tidy and confirm it no longer tries to download an unavailable go1.22 toolchain.

Written by the indexing model from the issue text.