lib/upgrade: Send OS version header to upgrade server (#9663)

This adds a header with the operating system version, verbatim in
whatever format the operating system reports it, to the upgrade check.
The intention is that the upgrade server can use this information to
filter out (or maybe just mark) potentially unsupported upgrades.

go.mod

@@ -31,7 +31,7 @@ require (
 	github.com/quic-go/quic-go v0.46.0
 	github.com/rabbitmq/amqp091-go v1.10.0
 	github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475
-	github.com/shirou/gopsutil/v3 v3.24.5
+	github.com/shirou/gopsutil/v4 v4.24.7
 	github.com/syncthing/notify v0.0.0-20210616190510-c6b7342338d2
 	github.com/syndtr/goleveldb v1.0.1-0.20220721030215-126854af5e6d
 	github.com/thejerf/suture/v4 v4.0.5
@@ -66,6 +66,7 @@ require (
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/hashicorp/go-multierror v1.1.1 // indirect
+	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/nxadm/tail v1.4.11 // indirect
 	github.com/onsi/ginkgo/v2 v2.20.0 // indirect
@@ -79,8 +80,11 @@ require (
 	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/riywo/loginshell v0.0.0-20200815045211-7d26008be1ab // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/shoenig/go-m1cpu v0.1.6 // indirect
 	github.com/stretchr/objx v0.5.2 // indirect
 	github.com/stretchr/testify v1.9.0 // indirect
+	github.com/tklauser/go-sysconf v0.3.12 // indirect
+	github.com/tklauser/numcpus v0.6.1 // indirect
 	github.com/yusufpapurcu/wmi v1.2.4 // indirect
 	go.uber.org/mock v0.4.0 // indirect
 	golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa // indirect