Update Go version to 1.26.0

See the release history: https://go.dev/doc/devel/release#go1.26.0.

Author: arnested

go.mod

@@ -1,6 +1,6 @@
 module github.com/arnested/systemd-state
 
-go 1.25.7
+go 1.26.0
 
 require (
 	github.com/coreos/go-systemd/v22 v22.7.0