Southwest Airlines Co. has agreed to make nearly $6 million in retirement payments and provide sick leave potentially worth north of $13 million to end a California federal suit alleging it denied benefits for brief spurts of military service to a proposed class of as many as 2,000 pilots. The deal, described in a motion for settlement approval and conditional class certification filed Thursday, will end allegations Southwest violated the Uniformed Services Employment and Reemployment Rights Act by not letting pilots accrue sick leave while on short-term military leave, or STML, and by not...