Remove redundant, language-specific aliases for KC_ALGR (#4720)

* Use standard KC_ALGR, remove language-specific redefinitions

* Use ALGR instead of ALTGR in BÉPO and Canadian multilingual keymaps

* Remove BE_LALT, BE_LGUI aliases

quantum/keymap_extras/keymap_uk.h

@@ -18,9 +18,6 @@
 
 #include "keymap.h"
 
-// Alt gr
-#define UK_ALGR KC_RALT
-
 // Normal characters
 #define UK_HASH KC_NUHS
 #define UK_BSLS	KC_NUBS