Promote GOMEMLIMIT and GOMAXPROCS featuregate to stable

[frzifus]

opentelemetry-operator/pkg/featuregate/featuregate.go

Lines 32 to 35 in ab7ef48

	SetGolangFlags = featuregate.GlobalRegistry().MustRegister(
	"operator.golang.flags",
	featuregate.StageAlpha,
	featuregate.WithRegisterDescription("enables feature to set GOMEMLIMIT and GOMAXPROCS automatically"),

We may want to skip GOMAXPROCS: https://go.dev/blog/container-aware-gomaxprocs