fix(compose): correct string interpolation in MongoDB feature compatibility version check

.devcontainer/compose.yml

@@ -45,10 +45,10 @@ services:
         const target = '8.2';
         const result = db.adminCommand({ getParameter: 1, featureCompatibilityVersion: 1 });
         if (result.featureCompatibilityVersion.version === target) {
-          print(`FCV already ${target}`);
+          print(`FCV already $${target}`);
         } else {
           db.adminCommand({ setFeatureCompatibilityVersion: target, confirm: true });
-          print(`FCV upgraded: ${result.featureCompatibilityVersion.version} -> ${target}`);
+          print(`FCV upgraded: $${result.featureCompatibilityVersion.version} -> $${target}`);
         }
 
   # This container requires '../../growi-docker-compose' repository