Revert "IPC Tag Project (#8649)"

This reverts commit f076f391f4.

code/unit_tests/sql_tests.dm

@@ -17,14 +17,12 @@ var/DBConnection/dbcon_ut
 	var/faults = 0
 	var/valid_columns = list()
 
-	// this is the worst unit test in the history of unit tests - geeves
 	var/list/table_names = list(
 		"ss13_characters",
 		"ss13_characters_flavour",
 		"ss13_player",
 		"ss13_player_preferences",
-		"ss13_player_pai",
-		"ss13_characters_ipc_tags"
+		"ss13_player_pai"
 	)
 	for (var/T in table_names)
 		var/DBQuery/get_cs = dbcon_ut.NewQuery("SELECT `COLUMN_NAME` FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE `TABLE_NAME` = :table:")