MM-53032: Fix module path after repo rename (#23689)

It was a good decision in hindsight to keep the public module as 0.x
because this would have been a breaking change again.

https://mattermost.atlassian.net/browse/MM-53032
```release-note
Changed the Go module path from github.com/mattermost/mattermost-server/server/v8 to github.com/mattermost/mattermost/server/v8.

For the public facing module, it's path is also changed from github.com/mattermost/mattermost-server/server/public to github.com/mattermost/mattermost/server/public
```

server/channels/store/sqlstore/store.go

@@ -30,11 +30,11 @@ import (
 	mbindata "github.com/mattermost/morph/sources/embedded"
 	"github.com/pkg/errors"
 
-	"github.com/mattermost/mattermost-server/server/public/model"
-	"github.com/mattermost/mattermost-server/server/public/shared/mlog"
-	"github.com/mattermost/mattermost-server/server/v8/channels/db"
-	"github.com/mattermost/mattermost-server/server/v8/channels/store"
-	"github.com/mattermost/mattermost-server/server/v8/einterfaces"
+	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/mlog"
+	"github.com/mattermost/mattermost/server/v8/channels/db"
+	"github.com/mattermost/mattermost/server/v8/channels/store"
+	"github.com/mattermost/mattermost/server/v8/einterfaces"
 )
 
 type migrationDirection string
@@ -118,7 +118,7 @@ type SqlStoreStores struct {
 
 type SqlStore struct {
 	// rrCounter and srCounter should be kept first.
-	// See https://github.com/mattermost/mattermost-server/server/v8/channels/pull/7281
+	// See https://github.com/mattermost/mattermost/server/v8/channels/pull/7281
 	rrCounter int64
 	srCounter int64