refactor: adjust build directives for go 1.17

Author: JanDeDobbeleer

src/constants_unix.go

@@ -1,4 +1,4 @@
-// +build !windows
+//go:build !windows
 
 package main
 

src/constants_windows64.go

@@ -1,5 +1,4 @@
-// +build windows
-// +build amd64
+//go:build windows && amd64
 
 package main
 

src/constrants_windows386.go

@@ -1,5 +1,4 @@
-// +build windows
-// +build 386
+//go:build windows && 386
 
 package main
 

src/environment_unix.go

@@ -1,4 +1,4 @@
-// +build !windows
+//go:build !windows
 
 package main
 

src/environment_windows.go

@@ -1,4 +1,4 @@
-// +build windows
+//go:build windows
 
 package main
 

src/environment_windows_win32.go

@@ -1,4 +1,4 @@
-// +build windows
+//go:build windows
 
 package main
 

src/segment_command_test.go

@@ -1,4 +1,4 @@
-// +build !windows
+//go:build !windows
 
 package main
 

src/segment_spotify_darwin.go

@@ -1,4 +1,4 @@
-// +build darwin
+//go:build darwin
 
 package main
 

src/segment_spotify_darwin_test.go

@@ -1,4 +1,4 @@
-// +build darwin
+//go:build darwin
 
 package main
 

src/segment_spotify_others.go

@@ -1,5 +1,4 @@
-// +build !darwin
-// +build !windows
+//go:build !darwin && !windows
 
 package main