Don't provide a button to copy estimated retention into desired retention

It's too easy for the user to end up with silly values if their configured
time/day is not reasonable.

ftl/core/deck-config.ftl

@@ -338,7 +338,7 @@ deck-config-get-params = Get Params
 deck-config-fsrs-on-all-clients =
     Please ensure all of your Anki clients are Anki(Mobile) 23.10+ or AnkiDroid 2.17+. FSRS will
     not work correctly if one of your clients is older.
-deck-config-set-optimal-retention = Set desired retention to { $num }
+deck-config-estimated-retention = Estimated retention: { $num }
 deck-config-complete = { $num }% complete.
 deck-config-reschedule-cards-on-change = Reschedule cards on change
 

ts/deck-options/FsrsOptions.svelte

@@ -188,18 +188,11 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         return tr.deckConfigComplete({ num: pct });
     }
 
-    function stringForSetOptimalRetention(retention: number): String {
+    function estimatedRetention(retention: number): String {
         if (!retention) {
             return "";
         }
-        return tr.deckConfigSetOptimalRetention({ num: retention.toFixed(2) });
-    }
-
-    function setDesiredRetentionToOptimal() {
-        if (!optimalRetention) {
-            return;
-        }
-        $config.desiredRetention = optimalRetention;
+        return tr.deckConfigEstimatedRetention({ num: retention.toFixed(2) });
     }
 </script>
 
@@ -319,14 +312,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         </button>
 
         {#if optimalRetention}
-            <button
-                class="btn {'btn-primary'}"
-                disabled={!optimalRetention ||
-                    optimalRetention === $config.desiredRetention}
-                on:click={() => setDesiredRetentionToOptimal()}
-            >
-                {stringForSetOptimalRetention(optimalRetention)}
-            </button>
+            {estimatedRetention(optimalRetention)}
         {/if}
         <div>{computeRetentionProgressString}</div>
     </details>