add codespell action (#18818)

Original work here, #18474,  refixed and updated.

cmd/global-heal.go

@@ -433,7 +433,7 @@ func (er *erasureObjects) healErasureSet(ctx context.Context, buckets []string,
 			partial: func(entries metaCacheEntries, _ []error) {
 				entry, ok := entries.resolve(&resolver)
 				if !ok {
-					// check if we can get one entry atleast
+					// check if we can get one entry at least
 					// proceed to heal nonetheless.
 					entry, _ = entries.firstFound()
 				}