Fix build from source with Spade tree-sitter grammar

[enkodr]

I've been having the following error building from source because the Spade language server has a trailing forward slash.

  --- stdout                                                                                                                                                                            
  Fetching 214 grammars                                                                                                                                                                 
  213 up to date git grammars                                                                                                                                                           
  Failure 1/1: spade Git command failed.                                                                                                                                                
  Stdout:                                                                                                                                                                               
  Stderr: remote:                                                                                                                                                                       
  remote: ========================================================================                                                                                                      
  remote:                                                                                                                                                                               
  remote: ERROR: The namespace you were looking for could not be found.

  remote: 
  remote: ========================================================================
  remote: 
  fatal: Could not read from remote repository.

  Please make sure you have the correct access rights
  and the repository exists.