Chore: Replace go-multierror with errors package

[iSatVeerSingh]

What is this feature?

Replaced go-multierror package with errors package.

Why do we need this feature?

Who is this feature for?

Which issue(s) does this PR fix?:

Fixes #63686

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.

[papagian]

Thank you for your contribution! I think that, now, after upgrading the target Go version to 1.20 we can merge it.
it would be nice to update also the go.mod (by syncing your branch with the latest main and run go mod tidy) so that the dependency becomes indirect.

[papagian]

@iSatVeerSingh have you closed it by accident? I think that we a few additional changes we could have merged it
shall I re-open it?

[papagian]

@iSatVeerSingh can you try to follow the instructions and resolve the conflict: the pkg/codegen/diffwrite.go has been deleted from the main branch therefore you need to remove it also from your branch
(I don't have permission to push to your branch to update it myself)

also can you please run go mod tidy and push the change in the go.mod file as well, thank you!

[iSatVeerSingh]

@papagian I run go mod tidy. It is adding //indirect instead of removing package

[grobinson-grafana]

Hi! 👋 You have some lint errors that are causing the build to fail:

pkg/services/ngalert/state/cache_test.go:69:3: S1021: should merge variable declaration with assignment on next line (gosimple)
		var multierr []error
		^
pkg/services/ngalert/state/cache_test.go:105:3: S1021: should merge variable declaration with assignment on next line (gosimple)
		var multierr []error
		^
pkg/services/ngalert/state/cache_test.go:71:19: errorsas: second argument to errors.As must be a non-nil pointer to either a type that implements error, or to any interface type (govet)
		require.True(t, errors.As(err, &multierr))
		                ^
pkg/services/ngalert/state/cache_test.go:107:19: errorsas: second argument to errors.As must be a non-nil pointer to either a type that implements error, or to any interface type (govet)
		require.True(t, errors.As(err, &multierr))

[papagian]

@papagian I run go mod tidy. It is adding //indirect instead of removing package

I think, that's fine; it's because another library we import uses it:

go mod why github.com/hashicorp/go-multierror
# github.com/hashicorp/go-multierror
github.com/grafana/grafana/pkg/codegen
github.com/grafana/codejen
github.com/hashicorp/go-multierror

[papagian]

I left some suggestions for fixing the tests

[iSatVeerSingh]

@papagian Added some changes. All the backend tests are passing on my local system.

[iSatVeerSingh]

I don't know why it is getting lint errors.

[papagian]

regarding the lint failures I think it's fine to ignore them for the tests

I cannot reproduce the memcached integration test failure locally and I think it's not related to the changes (must be a flaky test): let's give it a 2nd try

[papagian]

I think we hit a linter limitation here: in any case I think that it's fine to ignore the linter

Suggested change

	multierr, is := err.(interface{ Unwrap() []error })
	//nolint:errorlint
	multierr, is := err.(interface{ Unwrap() []error })

[papagian]

same as above

Suggested change

	multierr, is := err.(interface{ Unwrap() []error })
	//nolint:errorlint
	multierr, is := err.(interface{ Unwrap() []error })

[papagian]

thank you for your contribution!