diffoscope: disable test depending on black, re-enable fixed test

pkgs/tools/misc/diffoscope/default.nix

@@ -50,7 +50,7 @@ python3Packages.buildPythonApplication rec {
       xz zip zstd
     ]
     ++ (with python3Packages; [
-      argcomplete black debian defusedxml jsondiff jsbeautifier libarchive-c
+      argcomplete debian defusedxml jsondiff jsbeautifier libarchive-c
       python_magic progressbar33 pypdf2 rpm tlsh
     ])
     ++ lib.optionals stdenv.isLinux [ python3Packages.pyxattr acl cdrkit dtc ]
@@ -66,20 +66,19 @@ python3Packages.buildPythonApplication rec {
     installManPage doc/diffoscope.1
   '';
 
-  # Disable flaky test and a failing one
   disabledTests = [
+    # Disable flaky test and a failing one
     "test_android_manifest"
     "test_sbin_added_to_path"
     "test_diff_meta"
     "test_diff_meta2"
     "test_obj_no_differences"
 
-    # Failing because of file-v5.40 has a slightly different output.
-    # Upstream issue: https://salsa.debian.org/reproducible-builds/diffoscope/-/issues/271
-    "test_text_proper_indentation"
-
     # fails because it fails to determine llvm version
     "test_item3_deflate_llvm_bitcode"
+
+    # disable formatting tests because they can break on black updates
+    "test_code_is_black_clean"
   ] ++ lib.optionals stdenv.isDarwin [
     # Disable flaky tests on Darwin
     "test_non_unicode_filename"