LibJS: Add space in output of toEval in test-common.js

Author: https://github.com/davidot
Commit: 49fc0e2514
Pull-request: https://github.com/SerenityOS/serenity/pull/16094
Reviewed-by: https://github.com/linusg

Userland/Libraries/LibJS/Tests/test-common.js

@@ -381,7 +381,7 @@ class ExpectationError extends Error {
             this.__expect(
                 this.inverted ? !success : success,
                 () =>
-                    `Expected _${valueToString(this.target)}_` +
+                    `Expected _${valueToString(this.target)}_ ` +
                     (this.inverted ? "not to eval but it did" : "to eval but it didn't")
             );
         }