test: suppress DSR wait warning when running tests (#38126)

Problem:
The DSR wait warning causes any test that involves Nvim TUI to become
flaky on Windows. Example:

FAILED   test/functional/terminal/cursor_spec.lua @ 367: :terminal cursor can be positioned arbitrarily
test/functional/terminal\cursor_spec.lua:377: Row 1 did not match.
Expected:
  |*^                                                  |
  |*~                                                 |
  |*~                                                 |
  |*~                                                 |
  |*~                                                 |
  |*                                                  |
  |{5:-- TERMINAL --}                                    |
Actual:
  |*                                                  |
  |*                                                  |
  |*{2:                                                  }|
  |*{103:defaults.lua: Did not detect DSR response from ter}|
  |*{103:minal. This results in a slower startup time.     }|
  |*{UNEXPECTED foreground = tonumber('0x000006'):Press ENTER or type command to continue^           }|
  |{5:-- TERMINAL --}                                    |

Solution:
Don't show the DSR wait warning when running tests.

0 files changed, 0 insertions, 0 deletions