fix(slickvpn/updater): only keep 11 servers

- this reverts most of commit e806fe02db.

internal/storage/hardcoded.go

@@ -19,9 +19,3 @@ func parseHardcodedServers() (allServers models.AllServers, err error) {
 	err = decoder.Decode(&allServers)
 	return allServers, err
 }
-
-// HardcodedServers returns the hardcoded servers.
-// Warning: mutating the returned value will impact the storage's internal state.
-func (s *Storage) HardcodedServers() models.AllServers {
-	return s.hardcodedServers
-}

internal/storage/read.go

@@ -12,7 +12,7 @@ import (
 	"golang.org/x/text/language"
 )
 
-// readFromFile reads the servers from servers.json.
+// readFromFile reads the servers from server.json.
 // It only reads servers that have the same version as the hardcoded servers version
 // to avoid JSON decoding errors.
 func (s *Storage) readFromFile(filepath string, hardcodedVersions map[string]uint16) (