chg: usr: Optimize the TCP source port selection on Linux

Enable a socket option on the outgoing TCP sockets to allow faster selection of the source <address,port> tuple for different destination <address,port> tuples when nearing over 70-80% of the source port utilization.

Merge branch 'improve-selection-of-outgoing-TCP-port' into 'main'

See merge request isc-projects/bind9!11569