Docs: align the param spec of sqlite3.Connection methods with the imp…

…lementation (python#108285)

- no parameters of create_aggregate() are positional-only
- all parameters of create_collation() are positional-only

Doc/library/sqlite3.rst

@@ -764,7 +764,7 @@ Connection objects
          ('acbd18db4cc2f85cedef654fccc4a4d8',)
 
 
-   .. method:: create_aggregate(name, /, n_arg, aggregate_class)
+   .. method:: create_aggregate(name, n_arg, aggregate_class)
 
       Create or remove a user-defined SQL aggregate function.
 
@@ -904,7 +904,7 @@ Connection objects
 
          [('a', 9), ('b', 12), ('c', 16), ('d', 12), ('e', 9)]
 
-   .. method:: create_collation(name, callable)
+   .. method:: create_collation(name, callable, /)
 
       Create a collation named *name* using the collating function *callable*.
       *callable* is passed two :class:`string <str>` arguments,