Ensure executable bit is kept on the web editor (#10607)

Co-authored-by: Antoine GIRARD <sapk@users.noreply.github.com>

modules/repofiles/update.go

 
 	encoding := "UTF-8"
 	bom := false
+	executable := false
 
 	if !opts.IsNewFile {
 		fromEntry, err := commit.GetTreeEntryByPath(fromTreePath)
 			return nil, models.ErrSHAOrCommitIDNotProvided{}
 		}
 		encoding, bom = detectEncodingAndBOM(fromEntry, repo)
+		executable = fromEntry.IsExecutable()
 	}
 
 	// For the path where this file will be created/updated, we need to make
 	}
 
 	// Add the object to the index
-	if err := t.AddObjectToIndex("100644", objectHash, treePath); err != nil {
-		return nil, err
+	if executable {
+		if err := t.AddObjectToIndex("100755", objectHash, treePath); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := t.AddObjectToIndex("100644", objectHash, treePath); err != nil {
+			return nil, err
+		}
 	}
 
 	// Now write the tree