Test: remove verbose to make output more deterministic

Signed-off-by: Paul-Elliot <peada@free.fr>

Author: panglesd

test/blackbox-tests/test-cases/promote/deep-subdir.t

@@ -9,12 +9,12 @@ Tests for promoting directory targets
   $ cat > dune << EOF
   > (rule
   >  (deps
-  >    (source_tree deep))
+  >   (source_tree deep))
   >  (targets
-  >    (dir deep_copied))
+  >   (dir deep_copied))
   >  (mode promote)
   >  (action
-  >    (run cp -r deep deep_copied)))
+  >   (run cp -r deep deep_copied)))
   > EOF
 
 Let's create the directory structure we are going to promote (as a copy on
@@ -35,33 +35,16 @@ This one works. Now, let's add a layer between base_file and deep_file:
   $ touch deep/a/b/deep_file
   $ touch deep/base_file
 
-  $ dune build deep_copied --verbose
-  Shared cache: enabled-except-user-rules
-  Shared cache location: /home/panglesd/.cache/dune/db
-  Workspace root:
-  $TESTCASE_ROOT
-  Dune context:
-   { name = "default"
-   ; kind = "default"
-   ; profile = Dev
-   ; merlin = true
-   ; fdo_target_exe = None
-   ; build_dir = In_build_dir "default"
-   ; instrument_with = []
-   }
-  Actual targets:
-  - _build/default/deep_copied
-  Running[1]: (cd _build/default && /usr/bin/cp -r deep deep_copied)
-  Promoting "_build/default/deep_copied/a/b/deep_file" to
-  "deep_copied/a/b/deep_file"
-  File "dune", lines 1-7, characters 0-121:
+  $ dune build deep_copied
+  File "dune", lines 1-8, characters 0-123:
   1 | (rule
   2 |  (deps
   3 |   (source_tree deep))
-  4 |  (targets (dir deep_copied))
-  5 |  (mode promote)
-  6 |  (action
-  7 |   (run cp -r deep deep_copied)))
+  4 |  (targets
+  5 |   (dir deep_copied))
+  6 |  (mode promote)
+  7 |  (action
+  8 |   (run cp -r deep deep_copied)))
   Error: Cannot promote files to "deep_copied/a/b".
   Reason: opendir(deep_copied/a/b): No such file or directory
   -> required by _build/default/deep_copied