Revert "test: re-enable sync in TEST-25-IMPORT"

This shouldn't be necessary anymore, as we don't block openat2() when
running nspawn with --suppress-sync=yes.

This reverts commit c955e24916.

test/integration-tests/TEST-25-IMPORT/meson.build

@@ -3,8 +3,5 @@
 integration_tests += [
         integration_test_template + {
                 'name' : fs.name(meson.current_source_dir()),
-                # Newer tar started using openat2() (without openat() fallback) which
-                # we currently filter out completely in nspawn with --suppress-sync
-                'suppress-sync' : false,
         },
 ]