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/mining/laborcamp/laborshuttle.dm

@@ -24,4 +24,4 @@
 		if(S && S.name == "laborcamp_away")
 			to_chat(usr, "<span class='warning'>Shuttle is already at the outpost!</span>")
 			return 0
-	..()
+	..()

code/modules/mining/machine_unloading.dm

@@ -28,4 +28,4 @@
 			limit++
 			if (limit>=10)
 				return
-			CHECK_TICK
+			CHECK_TICK