v8.0 module release (#22975)

https://mattermost.atlassian.net/browse/MM-52079

```release-note
We upgrade the module version to 8.0. The new module path is github.com/mattermost-server/server/v8.
```


Co-authored-by: Doug Lauder <wiggin77@warpmail.net>

server/platform/services/slackimport/converters.go

@@ -8,7 +8,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/mattermost/mattermost-server/v6/server/platform/shared/mlog"
+	"github.com/mattermost/mattermost-server/server/v8/platform/shared/mlog"
 )
 
 func slackConvertTimeStamp(ts string) int64 {

server/platform/services/slackimport/parsers.go

@@ -7,8 +7,8 @@ import (
 	"encoding/json"
 	"io"
 
-	"github.com/mattermost/mattermost-server/v6/model"
-	"github.com/mattermost/mattermost-server/v6/server/platform/shared/mlog"
+	"github.com/mattermost/mattermost-server/server/v8/model"
+	"github.com/mattermost/mattermost-server/server/v8/platform/shared/mlog"
 )
 
 func slackParseChannels(data io.Reader, channelType model.ChannelType) ([]slackChannel, error) {

server/platform/services/slackimport/slackimport.go

@@ -18,12 +18,12 @@ import (
 	"time"
 	"unicode/utf8"
 
-	"github.com/mattermost/mattermost-server/v6/model"
-	"github.com/mattermost/mattermost-server/v6/server/channels/app/request"
-	"github.com/mattermost/mattermost-server/v6/server/channels/store"
-	"github.com/mattermost/mattermost-server/v6/server/channels/utils"
-	"github.com/mattermost/mattermost-server/v6/server/platform/shared/i18n"
-	"github.com/mattermost/mattermost-server/v6/server/platform/shared/mlog"
+	"github.com/mattermost/mattermost-server/server/v8/channels/app/request"
+	"github.com/mattermost/mattermost-server/server/v8/channels/store"
+	"github.com/mattermost/mattermost-server/server/v8/channels/utils"
+	"github.com/mattermost/mattermost-server/server/v8/model"
+	"github.com/mattermost/mattermost-server/server/v8/platform/shared/i18n"
+	"github.com/mattermost/mattermost-server/server/v8/platform/shared/mlog"
 )
 
 type slackChannel struct {

server/platform/services/slackimport/slackimport_test.go

@@ -12,10 +12,10 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/mattermost/mattermost-server/v6/model"
-	"github.com/mattermost/mattermost-server/v6/server/channels/app/request"
-	"github.com/mattermost/mattermost-server/v6/server/channels/store/storetest/mocks"
-	"github.com/mattermost/mattermost-server/v6/server/platform/shared/mlog"
+	"github.com/mattermost/mattermost-server/server/v8/channels/app/request"
+	"github.com/mattermost/mattermost-server/server/v8/channels/store/storetest/mocks"
+	"github.com/mattermost/mattermost-server/server/v8/model"
+	"github.com/mattermost/mattermost-server/server/v8/platform/shared/mlog"
 )
 
 func TestSlackConvertTimeStamp(t *testing.T) {