Fix knockback physics crash (#3715)

Author: Omena0

lib/plugins/physics.js

@@ -296,7 +296,10 @@ function inject (bot, { physicsEnabled, maxCatchupTicks }) {
     // TODO: emit an explosion event with more info
     if (bot.physicsEnabled && bot.game.gameMode !== 'creative') {
       if (explosion.playerKnockback) { // 1.21.3+
-        bot.entity.velocity.add(explosion.playerMotionX, explosion.playerMotionY, explosion.playerMotionZ)
+        // Fixes issue #3635
+        bot.entity.velocity.x += explosion.playerKnockback.x
+        bot.entity.velocity.y += explosion.playerKnockback.y
+        bot.entity.velocity.z += explosion.playerKnockback.z
       }
       if ('playerMotionX' in explosion) {
         bot.entity.velocity.x += explosion.playerMotionX