[TECH DEBT] Remove salt.payload.Serial

[Ch3LL]

236 class Serial:                                                                                                                                    
237 +---  4 lines: """-------------------------------------------------------------------------------------------------------------------------------
241                                                                                                                                                  
242     def __init__(self, *args, **kwargs):                                                                                                         
243         salt.utils.versions.warn_until(                                                                                                          
244             "Chlorine",                                                                                                                          
245             "The `salt.payload.Serial` class has been deprecated, "                                                                              
246             "and is set to be removed in {version}. "                                                                                            
247             "Please use `salt.payload.loads` and `salt.payload.dumps`.",                                                                         
248         )                                                                                                                                        
249                              

salt.payload.Serial has previously been deprecated and needs to be removed in 3007.0