chore: bump ls protocol version to 18 (#571)

src/snyk/common/constants/languageServer.ts

@@ -2,7 +2,7 @@
 // Language Server name, used e.g. for the output channel
 export const SNYK_LANGUAGE_SERVER_NAME = 'Snyk Language Server';
 // The internal language server protocol version for custom messages and configuration
-export const PROTOCOL_VERSION = 17;
+export const PROTOCOL_VERSION = 18;
 
 // LS protocol methods (needed for not having to rely on vscode dependencies in testing)
 export const DID_CHANGE_CONFIGURATION_METHOD = 'workspace/didChangeConfiguration';