utils: Drop MaxInt

[oxzi]

A generic max function was added to Go in version 1.21, making the utils.MaxInt obsolete. Outside, it was not used in neither icingadb, icinga-notifications nor icinga-kubernetes.

$ for project in icingadb icinga-notifications icinga-kubernetes; do pushd "$project"; git checkout main; git pull; grep -r "MaxInt"; popd; done
~/git/github.com/Icinga/icingadb ~/git/github.com/Icinga
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cmd/icingadb-migrate/cache.go:                          checkpoint = math.MaxInt64 // start from the largest (possible) ID
cmd/icingadb-migrate/main.go:           ht.fromId = math.MaxInt64
grep: icingadb-migrate: binary file matches
grep: icingadb: binary file matches
~/git/github.com/Icinga
~/git/github.com/Icinga/icinga-notifications ~/git/github.com/Icinga
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internal/rule/condition.go:const RetryNever = time.Duration(math.MaxInt64)
~/git/github.com/Icinga
~/git/github.com/Icinga/icinga-kubernetes ~/git/github.com/Icinga
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pkg/schema/v1/pod.go:           p.CpuLimits = MaxInt(p.CpuLimits, container.Resources.Limits.Cpu().MilliValue())
pkg/schema/v1/pod.go:           p.CpuRequests = MaxInt(p.CpuRequests, container.Resources.Requests.Cpu().MilliValue())
pkg/schema/v1/pod.go:           p.MemoryLimits = MaxInt(p.MemoryLimits, container.Resources.Limits.Memory().MilliValue())
pkg/schema/v1/pod.go:           p.MemoryRequests = MaxInt(p.MemoryRequests, container.Resources.Requests.Memory().MilliValue())
pkg/schema/v1/utils.go:func MaxInt[T constraints.Integer](x, y T) T {
~/git/github.com/Icinga