only reset idle counter on beast defeat (#552)

* on v1.0.0 the idle counter is reset on every attack
* adventurers can exploit this during certain battles to significantly prolong the duration of the battle which weakens the protection provided by the idle death penalty and global entropy sub-systems

contracts/game/src/lib.cairo

@@ -331,9 +331,6 @@ mod Game {
                 @self, immutable_adventurer, adventurer_id, game_entropy
             );
 
-            // update players last action block
-            adventurer.set_last_action_block(block_number);
-
             // process attack or apply idle penalty
             if !idle {
                 // get weapon specials
@@ -1099,6 +1096,9 @@ mod Game {
         // zero out beast health
         adventurer.beast_health = 0;
 
+        // update players last action block
+        adventurer.set_last_action_block(starknet::get_block_info().unbox().block_number);
+
         // get gold reward and increase adventurers gold
         let gold_earned = beast.get_gold_reward(beast_seed);
         let ring_bonus = adventurer.ring.jewelry_gold_bonus(gold_earned);