mathlib

2b397990 - chore(order/galois_connection): upgrade `is_glb_l` to `is_least_l` (#10606)

chore(order/galois_connection): upgrade `is_glb_l` to `is_least_l` (#10606) * upgrade `galois_connection.is_glb_l` to `galois_connection.is_least_l`; * upgrade `galois_connection.is_lub_l` to `galois_connection.is_greatest_l`.