feat: go upgrade 1.24

[ugurcanerdogan]

Summary

Upgrades the project-wide Go version from 1.19 to 1.24 and updates all related tooling to ensure full compatibility. Also fixes a nil pointer dereference bug in SetDefaults() that was exposed by Go 1.24's different goroutine scheduling behavior.

Changes

Go Version Upgrade (10 files)

All go.mod files updated from go 1.19 to go 1.24:

File	Change
go.mod	go 1.19 → go 1.24
test/integration/go.mod	go 1.19 → go 1.24
examples/single-consumer/go.mod	go 1.19 → go 1.24
examples/single-consumer-with-deadletter/go.mod	go 1.19 → go 1.24
examples/multiple-consumer/go.mod	go 1.19 → go 1.24
examples/single-consumer-with-producer/go.mod	go 1.19 → go 1.24
examples/single-consumer-with-custom-logger/go.mod	go 1.19 → go 1.24
examples/single-consumer-with-metric-collector/go.mod	go 1.19 → go 1.24
examples/single-consumer-with-backoff-strategy/go.mod	go 1.19 → go 1.24
examples/single-consumer-with-header-filter-function/go.mod	go 1.19 → go 1.24

GitHub Workflows (3 files)

• actions/checkout: v3 → v4
• actions/setup-go: v3 → v4
• goreleaser-action: v4 → v5
• golangci-lint-action: v3 → v6
• go-version: 1.19 → 1.24
• golangci-lint version: v1.51 → v1.64.8

golangci-lint Configuration (2 files)

golangci-lint v1.51 only supports up to Go 1.20. Updated to v1.64.8 (the last v1.x release with Go 1.24 support).

File	Change
Makefile	v1.51.0 → v1.64.8
.golangci.yml	Removed deprecated service block, removed depguard linter (requires explicit config in v1.64+)

Bug Fix: Nil Logger Panic

Problem: Config.SetDefaults() did not initialize the Logger field. In Go 1.19, tests completed before the cron job (@every 1s) fired, so the nil Logger was never accessed. Go 1.24's different goroutine scheduling caused the cron to fire during tests, triggering a nil pointer dereference at cronsumer_client.go:88.

Fix:

• pkg/kafka/config.go — Added automatic Logger initialization in SetDefaults() when Logger == nil
• pkg/kafka/config_test.go — Updated assertion to verify Logger is initialized rather than expecting nil

Lint Fixes (2 files)

The newer golangci-lint version introduced stricter checks:

File	Fix
internal/cronsumer_test.go	7 unused-parameter fixes (message → _, ctx → _, etc.)
internal/cronsumer_client_test.go	3 unused-parameter fixes (message → _)