small cleanups

[happygiraffe]

I noticed some minor upgrades were possible now we've updated to Go 1.24.
This should be a pure refactoring, with no semantic changes, and no performance impact.

[lemire]

Looks good, I will leave it open a few days to see if anyone has comments. Cheers!

[Copilot]

Pull Request Overview

This PR modernizes the codebase by replacing deprecated io/ioutil functions with their direct os package equivalents (introduced in Go 1.16) and updates iterator function signatures to use the standard iter.Seq type (introduced in Go 1.23). Additionally, it improves test hygiene by using t.TempDir() for temporary file management.

Key changes:

• Replaced ioutil.ReadFile, ioutil.WriteFile, ioutil.TempDir, and ioutil.TempFile with os.ReadFile, os.WriteFile, os.MkdirTemp, and os.CreateTemp
• Updated iterator function signatures from func(func(T) bool) to iter.Seq[T]
• Modified tests to use t.TempDir() for automatic cleanup of temporary files

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
smat_generate_test.go	Replaced ioutil.WriteFile with os.WriteFile and removed deprecated import
serialization_test.go	Replaced ioutil.ReadFile with os.ReadFile, used t.TempDir() for test file management, and removed manual cleanup
serialization_frozen_test.go	Replaced all ioutil.ReadFile calls with os.ReadFile and removed deprecated import
roaring64/serialization_test.go	Replaced ioutil functions with os equivalents, used t.TempDir() for proper test isolation
roaring64/bsi64_test.go	Updated to use os.CreateTemp with t.TempDir() and removed manual cleanup
iter.go	Updated iterator return types to use iter.Seq[uint32]
roaring64/iter.go	Updated iterator return types to use iter.Seq[uint64]

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[happygiraffe]

FYI, I observed an odd test failure on macos, and noticed that the github workflow was still on go 1.22, so I've also upgraded the workflows to use go 1.24.