test: disable flake (#12459)

Signed-off-by: Rudi Grinberg <[email protected]>

Author: rgrinberg

test/blackbox-tests/test-cases/exec-watch/dune

@@ -18,5 +18,9 @@
 ; These tests are explicitly disabled due to flakiness
 
 (cram
- (applies_to exec-watch-ignore-sigterm exec-signal exec-watch-basic)
+ (applies_to
+  exec-watch-server
+  exec-watch-ignore-sigterm
+  exec-signal
+  exec-watch-basic)
  (enabled_if false))