tests: turn off unit test verbosity

there's no real usefulness to this output in build logs. in interactive
development builds -v can be passed to meson to restore the old output.

Change-Id: Iac4c0573fd1cac5fc9044b950ef52ee50448e6fc

tests/unit/meson.build

@@ -97,7 +97,7 @@ test(
   },
   suite : 'check',
   protocol : 'gtest',
-  verbose : true,
+  verbose : false,
 )
 
 libstore_test_support_sources = files(
@@ -167,7 +167,7 @@ test(
   },
   suite : 'check',
   protocol : 'gtest',
-  verbose : true,
+  verbose : false,
 )
 
 libexpr_test_support_sources = files(
@@ -235,7 +235,7 @@ test(
   },
   suite : 'check',
   protocol : 'gtest',
-  verbose : true,
+  verbose : false,
 )
 
 libcmd_tester = executable(