We cannot compare against origin/main branch because we build from sdist, not git.

--- filelock-3.20.0/tox.toml.orig
+++ filelock-3.20.0/tox.toml
@@ -36,14 +36,6 @@
 
     "tests",
   ],
-  { replace = "posargs", extend = true, default = [
-    [
-      "diff-cover",
-      "--compare-branch",
-      { replace = "env", name = "DIFF_AGAINST", default = "origin/main" },
-      "{env_tmp_dir}{/}coverage.xml",
-    ],
-  ] },
 ]
 
 [env.coverage]
--- filelock-3.20.0/pyproject.toml.orig
+++ filelock-3.20.0/pyproject.toml
@@ -57,7 +57,6 @@
 
 test = [
   "covdefaults>=2.3",
-  "diff-cover>=9.7.1",
   "pytest>=8.4.2",
   "pytest-asyncio>=1.2",
   "pytest-cov>=7",