Fix typo in MetadataLoader.java (#2677)

determing -> determining

Co-authored-by: Dongie Agnir <[email protected]>

Author: Ikko Ashimine

core/regions/src/main/java/software/amazon/awssdk/regions/MetadataLoader.java

@@ -18,7 +18,7 @@
 import software.amazon.awssdk.annotations.SdkInternalApi;
 
 /**
- * Internal class for determing where to load region and service
+ * Internal class for determining where to load region and service
  * metadata from. Currently only generated region metadata is supported.
  */
 @SdkInternalApi