patch 8.2.0149: maintaining a Vim9 branch separately is more work

Problem:    Maintaining a Vim9 branch separately is more work.
Solution:   Merge the Vim9 script changes.
diff --git a/src/proto/blob.pro b/src/proto/blob.pro
index 706a83e..3bc6625 100644
--- a/src/proto/blob.pro
+++ b/src/proto/blob.pro
@@ -2,7 +2,7 @@
 blob_T *blob_alloc(void);
 int rettv_blob_alloc(typval_T *rettv);
 void rettv_blob_set(typval_T *rettv, blob_T *b);
-int blob_copy(typval_T *from, typval_T *to);
+int blob_copy(blob_T *from, typval_T *to);
 void blob_free(blob_T *b);
 void blob_unref(blob_T *b);
 long blob_len(blob_T *b);