chore(proto): change symlinktarget to be byte sequence (fixes #9913) (#9914)

lib/scanner/walk.go

@@ -740,7 +740,7 @@ func CreateFileInfo(fi fs.FileInfo, name string, filesystem fs.Filesystem, scanO
 		if err != nil {
 			return protocol.FileInfo{}, err
 		}
-		f.SymlinkTarget = target
+		f.SymlinkTarget = []byte(target)
 		f.NoPermissions = true // Symlinks don't have permissions of their own
 		return f, nil
 	}

lib/scanner/walk_test.go

@@ -367,7 +367,7 @@ func TestWalkSymlinkUnix(t *testing.T) {
 		if len(files[0].Blocks) != 0 {
 			t.Errorf("expected zero blocks for symlink, not %d", len(files[0].Blocks))
 		}
-		if files[0].SymlinkTarget != "../testdata" {
+		if string(files[0].SymlinkTarget) != "../testdata" {
 			t.Errorf("expected symlink to have target destination, not %q", files[0].SymlinkTarget)
 		}
 	}