Microsoft SQL Server CLOSE – PB Docs 2019

If a database stored procedure returns a result set, it must be
closed when processing is complete.

Closing a procedure looks the same as closing a cursor:

As with cursors, if a procedure executes successfully and returns at
least one result set and is not closed, a result set is pending and no SQL
commands other than the FETCH can be executed. Procedures with result sets
should be closed as soon as possible.

You do not have to retrieve all the rows in a result set to close a
request or procedure.