Fix Travis grep script to use PCRE to actually match things (#47065)

Several of the greps were missing the `-P` switch which caused them to 
fail to match things. The EOL grep also wasn't working right so I 
replaced it with the one I added to TGMC.

code/modules/spells/spell_types/explosion.dm

@@ -13,4 +13,4 @@
 			continue
 		explosion(target.loc,ex_severe,ex_heavy,ex_light,ex_flash)
 
-	return
+	return

code/modules/spells/spell_types/projectile.dm

@@ -127,4 +127,4 @@
 		if(new_turf.density)
 			break
 		T = new_turf
-	perform(list(T),user = user)
+	perform(list(T),user = user)

code/modules/spells/spell_types/trigger.dm

@@ -27,4 +27,4 @@
 		for(var/obj/effect/proc_holder/spell/spell in linked_spells)
 			spell.perform(list(target),0)
 
-	return
+	return