remove support of go 1.21

[ktong]

minimum go version is go 1.22 now

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 82.8%. Comparing base (d34da87) to head (5920226). Report is 41 commits behind head on main.

Additional details and impacted files

[](https://app.codecov.io/gh/nil-go/konf/pull/457?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=nil-go) ```diff @@ Coverage Diff @@ ## main #457 +/- ## ======================================= - Coverage 82.8% 82.8% -0.1% ======================================= Files 62 62 Lines 2652 2651 -1 ======================================= - Hits 2198 2197 -1 Misses 371 371 Partials 83 83 ``` | [Files](https://app.codecov.io/gh/nil-go/konf/pull/457?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=nil-go) | Coverage Δ | | |---|---|---| | [internal/convert/option.go](https://app.codecov.io/gh/nil-go/konf/pull/457?src=pr&el=tree&filepath=internal%2Fconvert%2Foption.go&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=nil-go#diff-aW50ZXJuYWwvY29udmVydC9vcHRpb24uZ28=) | `70.5% <100.0%> (ø)` | | | [internal/nocopy.go](https://app.codecov.io/gh/nil-go/konf/pull/457?src=pr&el=tree&filepath=internal%2Fnocopy.go&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=nil-go#diff-aW50ZXJuYWwvbm9jb3B5Lmdv) | `100.0% <100.0%> (ø)` | | | [provider/secretmanager/secretmanager.go](https://app.codecov.io/gh/nil-go/konf/pull/457?src=pr&el=tree&filepath=provider%2Fsecretmanager%2Fsecretmanager.go&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=nil-go#diff-cHJvdmlkZXIvc2VjcmV0bWFuYWdlci9zZWNyZXRtYW5hZ2VyLmdv) | `89.9% <ø> (-0.1%)` | :arrow_down: |