[Minor] fix error message (#7540)

### What changes were proposed in this pull request?

 Fix error message

### Why are the changes needed?

Clarity

Fix: #(issue)

### Does this PR introduce _any_ user-facing change?

No

### How was this patch tested?

CI

Co-authored-by: Justin Mclean <[email protected]>

Author: github-actions[bot]

core/src/main/java/org/apache/gravitino/utils/IsolatedClassLoader.java

@@ -172,7 +172,7 @@ protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundE
       try {
         return clazz == null ? doLoadClass(name, resolve) : clazz;
       } catch (Exception e) {
-        throw new ClassNotFoundException("Class no found " + name, e);
+        throw new ClassNotFoundException("Class not found " + name, e);
       }
     }