chore: add /v2 to import module path (#9072)

* chore: add /v2 to import module path

go mod requires semantic versioning with versions greater than 1.x

This was a mechanical update by running:
```
go install github.com/marwan-at-work/mod/cmd/mod@latest
mod upgrade
```

Migrate generated files to import /v2

* Fix gen

agent/agentssh/agentssh.go

@@ -28,10 +28,10 @@ import (
 
 	"cdr.dev/slog"
 
-	"github.com/coder/coder/agent/usershell"
-	"github.com/coder/coder/codersdk"
-	"github.com/coder/coder/codersdk/agentsdk"
-	"github.com/coder/coder/pty"
+	"github.com/coder/coder/v2/agent/usershell"
+	"github.com/coder/coder/v2/codersdk"
+	"github.com/coder/coder/v2/codersdk/agentsdk"
+	"github.com/coder/coder/v2/pty"
 )
 
 const (

agent/agentssh/agentssh_internal_test.go

@@ -15,8 +15,8 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/coder/coder/pty"
-	"github.com/coder/coder/testutil"
+	"github.com/coder/coder/v2/pty"
+	"github.com/coder/coder/v2/testutil"
 
 	"cdr.dev/slog/sloggers/slogtest"
 )

agent/agentssh/agentssh_test.go

@@ -20,9 +20,9 @@ import (
 
 	"cdr.dev/slog/sloggers/slogtest"
 
-	"github.com/coder/coder/agent/agentssh"
-	"github.com/coder/coder/codersdk/agentsdk"
-	"github.com/coder/coder/pty/ptytest"
+	"github.com/coder/coder/v2/agent/agentssh"
+	"github.com/coder/coder/v2/codersdk/agentsdk"
+	"github.com/coder/coder/v2/pty/ptytest"
 )
 
 func TestMain(m *testing.M) {

agent/agentssh/x11_test.go

@@ -19,9 +19,9 @@ import (
 
 	"cdr.dev/slog"
 	"cdr.dev/slog/sloggers/slogtest"
-	"github.com/coder/coder/agent/agentssh"
-	"github.com/coder/coder/codersdk/agentsdk"
-	"github.com/coder/coder/testutil"
+	"github.com/coder/coder/v2/agent/agentssh"
+	"github.com/coder/coder/v2/codersdk/agentsdk"
+	"github.com/coder/coder/v2/testutil"
 )
 
 func TestServer_X11(t *testing.T) {