Fix/add support for time

[hchienjo]

1. Add support for time in config.
2. Update dependencies.
3. Move to go1.24.1.
4. Fix linter warnings.

[philippgille]

I think it would make sense to split into distinct PRs, as some changes in this PR are unrelated to each other.

Then for some PRs we could discuss a bit more, while others could already be merged. For example:

• Fixing linter warnings (e.g. ioutil.TempDir usage): ✅
• Time: Useful new feature, but different from time.Duration it requires a pointer? Why not handle it the same way? Instead of a nil check people will have to do t.IsZero() and assume the time is not explicitly set to 0001-01-01..., but it's the same with the duration, no? Can both be supported?
• gopkg.in/yaml.v2 to v3 update: That one's outdated as well, so maybe worth moving to github.com/goccy/go-yaml, if the goal is to remove the usage of outdated dependencies? But can be two steps as well: One PR to bump to v3, another later to migrate to another library
• Removal of github.com/pkg/errors usage: While I think the consensus is that Go libraries shouldn't return stacktraces and I agree with it, it would be a breaking change for those that expect one to be returned. With confita being a public repo with 117 places importing it, do we want to do this?
• Go version update: Does any feature require 1.24.1 specifically? Otherwise I'd go with 1.23.0. People with newer toolchains won't be downgraded to it so no downside for them, but people with older tollchains aren't forced through Go's implicit version download without it being necessary

[skateinmars]

Time: Useful new feature, but different from time.Duration it requires a pointer? Why not handle it the same way? 

Agreed, let's be consistent

Go version update

Agreed, the usual strategy is to ensure the last 2 major releases are compatible

I'd also add that changing interface{} with any in the public interfaces could be technically considered a breaking change, so let's not include this for now. We could do a separate "cleanup" PR in anticipation of a major release, that includes the YAML lib change and pkg/errors removal.

[rogpeppe]

I'd also add that changing interface{} with any in the public interfaces could be technically considered a breaking change, so let's not include this for now.

Drive-by comment: as any is just a type alias for interface{} it is actually entirely interchangeable so it's OK to change any instance of interface{} to any without breaking strict API compatibility.

[hchienjo]

Superseded by #99.