go.mod: update to go1.25, use waitgroup.Go, and enable modernize linter

[thaJeztah]

• stacked on *: simplify range loops #3268

- How I did it

- How to test it

- Description for the changelog

[Copilot]

Pull request overview

Updates the SwarmKit codebase to target Go 1.25 and adopts new Go 1.25-era standard library conveniences (notably sync.WaitGroup.Go and typed atomics), while also enabling the modernize linter to enforce/encourage newer idioms.

Changes:

• Bump module/workspace Go version directives to Go 1.25.
• Replace several manual WaitGroup.Add/Done goroutine patterns with WaitGroup.Go.
• Modernize concurrency primitives (typed atomic.Uint32) and enable the modernize golangci-lint linter.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
watch/watch_test.go	Refactors benchmark goroutine spawning to use WaitGroup.Go.
swarmd/go.work	Bumps workspace Go version directive to 1.25.
swarmd/go.mod	Bumps swarmd module Go version directive to 1.25.
node/node.go	Uses WaitGroup.Go for node component goroutines and removes manual Add/Done.
manager/state/store/memory_test.go	Uses WaitGroup.Go in benchmark concurrency helpers.
manager/state/raft/raft.go	Switches uint32 atomics to typed atomic.Uint32 fields and updates call sites.
manager/orchestrator/update/updater.go	Uses WaitGroup.Go for worker goroutines (but currently leaves a blocking Add).
manager/logbroker/broker_test.go	Uses WaitGroup.Go for log publishing goroutines in tests.
manager/controlapi/service.go	Uses slices.Contains for reserved-name validation and adds slices import.
manager/allocator/allocator.go	Simplifies closure capture and uses WaitGroup.Go for allocator actor goroutine.
integration/cluster_test.go	Uses WaitGroup.Go in integration test node lifecycle goroutines and removes unused import.
go.mod	Bumps root module Go version directive to 1.25.
agent/worker.go	Uses WaitGroup.Go for concurrent log subscriptions.
.golangci.yml	Enables the modernize linter.

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[Copilot]

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

manager/logbroker/broker_test.go:88

• require.NoError(t, ...) is called inside a goroutine. If any of these assertions fail, testify's require will call t.FailNow, which is not safe from a non-test goroutine and can panic with "FailNow called from goroutine other than test goroutine". Prefer reporting errors without FailNow (e.g., explicit if err != nil { t.Errorf(...); return }) or send errors back to the main goroutine and require there after wg.Wait().

					publisher, err := brokerClient.PublishLogs(ctx)
					require.NoError(t, err)

					defer func() {
						_, err := publisher.CloseAndRecv()

[codecov-commenter]

Codecov Report

❌ Patch coverage is 60.00000% with 14 lines in your changes missing coverage. Please review.
✅ Project coverage is 14.71%. Comparing base (6e9e7b8) to head (8b8847d).
⚠️ Report is 46 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3269      +/-   ##
==========================================
- Coverage   14.73%   14.71%   -0.02%     
==========================================
  Files         200      200              
  Lines       93077    93027      -50     
==========================================
- Hits        13712    13689      -23     
+ Misses      78019    77993      -26     
+ Partials     1346     1345       -1     

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[thaJeztah]

Actually; probably should just use go 1.25.0 - #3257 would add the patch version back again either way, so we may as well just keep it.

[thaJeztah]

cc @corhere @vvoland ptal