test-progress: disable mocking-time tests on chg

It's hard to make these tests compatible with chg because a mocked time.time()
is recorded and accessed by progbar at random timing. I don't think it's worth
fixing this test as it is considered a unit test of time estimates, so just
ignores on chg.

tests/test-progress.t

@@ -182,6 +182,8 b' test immediate progress completion'
 
 test delay time estimates
 
+#if no-chg
+
   $ cat > mocktime.py <<EOF
   > import os
   > import time
@@ -250,6 +252,8 b' Time estimates should not fail when ther'
   loop [  <=>                                             ] 3\r (no-eol) (esc)
                                                               \r (no-eol) (esc)
 
+#endif
+
 test line trimming by '[progress] width', when progress topic contains
 multi-byte characters, of which length of byte sequence and columns in
 display are different from each other.